NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
On the Habits of Certain " Harvesting." Ants.
(WITH PLATE.)
Genus.—Holcomyrmex, Mayr.
(Described as a new genus—Mayr Verhand k.k. Zool-botan Gesell : Wein 1878.)
Species.—H. scabriceps, Mayr—H. criniceps, Mayr.
BY
SURGEON J. H. T. WALSH.
One day during January 1889 my attention was attracted by a long train of
ants which was wending its way across an unfrequented corner of the Puri Jai
compound. I noticed that all the ants who were hastening towards the nest
carried in their mandibles the seeds of certain grasses. In one or two cases two
or three ants were engaged in dragging along entire spikelets. Following the
train I came upon the nest, the opening to which was in the centre of a large
crater-like midden. The midden was composed of the sand dug out of the nest,
and over this, almost hiding it, lay a large quantity of chaff and husks from the
various seeds which the ants must have collected during the harvesting season.
Having read Moggridge's work on the harvesting ants of the south of France, I was
naturally much interested in this " find," and I examined the ants to see whether
they corresponded with the description which Moggridge gives of the harvesting
aphœnogasters. As the ants were quite strange to me I collected some, and at
the same time took some of the seeds and grasses. The seeds were identified
by Mr. Duthie and Dr. Prain as those of Eragrostis plumosa, Sporobolus (sp.?)
and Cynodon dactylon. The last-mentioned grass—the " dubh grass "—seemed
to be a great favourite with the ants. Through the courtesy of Mr. Cotes, of the
Indian Museum, the ants collected by me were forwarded to Professor A. Forel
for identification. Dr. Forel identified the ants as belonging to the species
Holcomyrmex scabriceps, Mayr, and in his letter noticed that Audré had already
supposed these ants to be " harvesters " from the appearance of the mandibles
I have referred to Audré's work, " Les Fourmis," and find that he merely men
tions Holcomyrmex as a harvesting genus, but gives no details. Dr. Forel fur-
ther pointed out that there are two other species belonging to this genus in India,
and I afterwards found nests of H. criniceps , Mayr ; but have not yet met with
the third species, H. glaber,Audré. There is a specimen of H. glaber in the
1. Scirpus barbatus.
2. Eragrostis plumosa.
3. Perotis latifolia.
4. Eleusine aegyptiaca.
5. Panicum indicum.
6. Amaranthus gangeticus.
7. Cynodon dactylon.
Scientific Memoirs by
remain more or less torpid, finding sufficient for their wants in the stores of grain
remaining at the end of the harvesting season. No doubt where the heat is less or
the nest sheltered, the ants work on up to the rains, and as I have shown they
occasionally come out even during the "rains," when there is an interval of fine
weather. In such cases the necessity for extensive storing would be lessened.
When we consider the formation of the mouth parts of an ant it seems evi-
dent that they cannot eat seeds which have become hard and dry, and must
store them until the starch in the seed is changing into sugar, when they tear
through the testa and suck out the sweet juice: "Exactement commeles chiens
lorsqu'ils lapent ou lorsqu'ils lèchent le fond d'une assiette" (Forel—Les
Fourmis de la Suisse, page 108). The uneaten debris is then carefully removed
from the nest and thrown on to the midden.
The object of storing is not only, in my opinion, to provide for the future,
since I believe the ants are nearly torpid all through the hot season, or may in
some cases go on working, but to allow the seeds time to become so altered that
they can be used as food. No doubt with fresh green seeds, many of which the
ants collect, the juices are sucked out at once without any storing. It is worthy
of notice that, although the "harvesters" collect seeds, from a great variety of
plants, they show a decided preference for grass seeds, probably because these
seeds contain a large amount of starch available as sugar when fermentation
takes place.
The following is a list of a few only of the plants and grasses from which I
have seen the ants cutting their crops:—
62
For the botanical names of the above I am much indebted to the kindness
of Mr. Duthie and Dr. Prain. These agricultural ants are a hard-working, peace-
ful race not given to fighting. They are not, however, wanting in courage and
will attack any strange ants placed close to their nest. Their sting is small
and feeble, but their strong mandibles would form excellent weapons of offence
or defence Their communities vary from small nests containing only a few
hundred individuals to large and long-established dwellings containing thousands.
With one large nest I made a rough calculation which gave at least eight
thousand as the population of the nest. The nests are generally solitary, and
Holcomyrmex do not form colonies of any extent as other ants do. H. scabriceps
and H. criniceps do not appear to harbour guests in their dwellings. I have oc-
casionally seen one or two Lepismidœ, but their presence was probably accidental.
On the midden there may almost always be found several small black beetles.
These probably feed on the vegetable débris and lay their eggs in the midden.
The ants never molest them, but seem to take no notice of them.
Medical Officers of the Army of India.
The harvesting ants of the south of India have been described by Sykes
and Jerdon and include Pheidole providens, West, This ant is not found in
Puri, but I have noticed that Pheidole indica, Mayr, sometimes carry fallen
seeds, though their chief food is insects. On the authority of Mr. Horn (ref.
Moggridge "Harvesting Ants and Trapdoor Spiders," pp. 66-67, edition 1873)
Sima(Pseudomyrma) rufo-nigra, Jerdon, is included among the harvesting ants.
It would be rash for me to say that this species does not harvest in some part
of India, but it certainly does not in Orissa. I have had several nests under ob-
servation in the neighbourhood of Puri for more than a year. Mr. Horn is
quoted (loc. cit.) as saying that the ants he noticed in Mainpuri were "of a
medium size, shortish bodies, and of a reddish brown colour.—Pseudomyrma
rufo-nigra." The ♀ o f
S i m a r u f o - n i g r a
m e a s u r e s 1 0 m m ; t h e h e a d , a b d o m e n a n d
2nd node of the petiole shiney brownish black; thorax and 1st node of the petiole
bright yellowish red; the body is long and slender; nest in the dry wood of
trees; food insects. Perhaps Mr. Horn did not correctly identify the ants seen
by him.
I have never seen Holcomyrmex bringing up seeds to dry after rain, nor
can I help to solve the problem as to why the seeds do not germinate in the
granaries. I have examined a great many seeds, but never saw any signs of
germination. Seeds taken at various periods have always germinated when
placed in moist warm earth. Perhaps, after all, there is not much mystery sur-
rounding the non-germination of the seeds in the granaries. All that is required
is that the seeds shall be kept dry, and this may be done with little trouble. No
doubt the ants examine their store-rooms frequently and use for immediate con-
sumption any seeds in which germination has commenced; or, biting off the
radicle, remove them to a drier part of the nest.
Dr. Forel tells me that the and ♀ of H. scabriceps have been, up
to the present, unknown, and I take this opportunity of describing the solitary
specimen of the which I dug out of a nest on the 7th October 1889. Her
wings had been stripped off and she was evidently about to lay her eggs. I
failed to detect the period of the conjugal flight, but suppose it to take place
some time in September; this supposition however needs confirmation. The
male I have not yet found.
Holcomyrmex scabriceps, Mayr ♀ ; (agrees generally with the generic deb-
..
scription given by Dr. Mayr). Length 10 mm. head 2 mm., thorax 3.4 mm.,
abdomen including the petiole nearly 5 mm. Mandibles black, stumpy, with
indistinct broad, blunt teeth, marked with a few coarse striæ and slightly hairy.
Antennæ dark reddish brown, 12 joints; scape inserted close to anterior margin
of head, richly covered with small hairs; when folded back does not reach to
the posterior angle of the head. Flagellum only moderately clubbed, apical
joint nearly as long as the two next, short strong hairs on the segments. Eyes
round, black, small and not prominent; ocelli, pearly white. Head ferruginous,
63
64 Scientific Memoirs by Medical Officers of the Army in India.
striated longitudinally and covered with very fine white hairs; head, without
mandibles, almost square, wider behind than in front, slightly concave behind in
the centre of the occipital margin, posterior angles rounded; the small triangular
portion of the vertex enclosed by the ocelli is reddish black and the angles ap-
pear raised to form partial sockets for the ocelli. Thorax nigro-ferruginous and
shining on the upper surface, lighter at the sides and beneath, somewhat
rugose at the sides and generally hairy; pronotum small, mesonotum large
and very convex in front, grooves between mesonotum, scutellum, post-scu-
tellum and metanotum distinct; basal portion of metanotum with slightly irre-
gular transverse striæ. First node of the petiole somewhat conical, rounded on
the top; second node round and almost sessile on the abdomen; color as head,
but lighter beneath and at the sides, upper surface of nodes darker than other
parts; a few strong hairs on the posterior aspect of each node, more marked on
the first. Abdomen brownish-black, shining, oval, truncated in front and not
very pointed behind, covered with small strong whitish hairs; first segment very
large, occupying half the abdomen. Legs: coxæ pale rust red, femora and
tibiae blackish brown and shining, tarsi rust red. Wings unknown.
The individuals which I have called soldiers are, with the head stretched
out, about. 75 mm. long and remarkable for the "elephantine" appearance
of the head, which measures 2.3 by 2 mm. in the widest part. What their parti-
cular functions may be I am not able to say with certainty; they do not harvest,
and their teeth are too blunt for seed-cleaning. They act, I think, as pioneers,
road-makers, &c., and with their large heads would be able to block up the
entrance to the nest in case of invasion. The measurements given by Dr.
Mayr for the major and ♀ m i n o r a r e 5 . 2 m m . a n d 3 . 8 m m . r e s p e c t i v e l y ,
and these correspond nearly with the specimens in my collections. The three
mandibular teeth are strong and well defined in the ♀ major, but are less sharp
than those of the small worker.
NOTE.—Since this paper was written and sent to the Editor, I have come across a note on the habits of
Holcomyrmex by Mr. G. A. J. Rothney, who observed them near Barrackpur. (I. Bomb, Nat. Hist. Soc.
No. 1, Vol. V, 1890, p. 57).—J. H. T. W., 10.2.91.
Description of Plate.
Holcomyrmex scabriceps.
a worker major (about natural size)
b
, , minor
, ,
C soldier
, ,
d female
, ,
A worker major
(enlarged).
B
„
minor
, ,
C soldier
, ,
D female
, ,
HARVESTING ANTS. (J. H. TULL WALSH.)
HOLCOMYRMEX SCABRICEPS (about natural size).
HOLCOMYRMEX SCABRICEPS (enlarged).
Reg. No. 194, San., India—26.6.90.—300.
Litho., S. I. O.,—Calcutta.
On two Autcecious Cæomata in Simla.
BY
SURGEON-MAJOR A. BARCLAY, M.B.
Two complete autcecious Comata occur in Simla, one on Smilax aspera, L.
and the other on Prenanthes Brunoniana, Wall and Lactuca macrorhiza, Hook. f.
The former I have already described in a preceding volume of these Memoirs,*
but I have since obtained further information regarding its life history, which I
will add here after describing the fungus on Prenanthes and Lactuca; and I shall
conclude with some general remarks on the genus Cooma.
I. Puccinia Prenanthes, Pers.
Var. Himalensis.
I have met with this fungus in two separate localities widely distant from
one another; in the one locality on Prenanthes Brunoniana and in the other on
Lactuca macrorhiza. The aacidial stage on Prenanthes is found during the latter
part of March and April and on Lactuca considerably later, but it is by no
means common. In March the leaves of Prenanthes were found in early attack,
bearing spermogonia and a few young cidia, not yet open, but in the case of Lac-
tuca this does not occur until June and July. The fungus causes considerable
hypertrophy and distortion. The leaf patches, which are about o.5 mm. in dia-
meter, on an average, on Prenanthes, are much paled in colour, usually deeply
concave above and convex below. spermogonia are numerous on both surfaces.
The petioles of leaves are also often found attacked, when they swell somewhat
and become distorted. The leaf patches are irregularly round or oval, and as
many as six may be found on a single leaf.
The cidia are all on the lower leaf surface, and open by a pore. There
is no peridium. The aecidia are very large, occupying almost the whole depth
of the leaf blade. The a2cidiospores are round oval or pyriform, pale yellowish
brown, and with a densely tuberculated epispore. The fresh spores from Pre-
nanthes measured from 21 p, in diameter to 28X20, or 23.5X20 p, on an
average (28-21X22-1.8), whilst those fromL a c t u c a '
m e a s u r e d 3 2 - 1 6 x 2 8 - 1 6
μ .
I could not detect any germ pores in the spores from Prenanthes even with sul-
phuric acid, which immediately bleached them; but those from Lactuca revealed
* Part IV, 1889.
K
Medical Officers of the Army of India.
This fungus is sufficiently like P. Prenanthis, Pers., to warrant its being so
named; but it is a distinct variety in that it has no vestige of peridium, and
in that its spore measurements are somewhat different from those given by
European observers, as shown in the following table:—
......
Aecidiospores.
Uredospores.
Teleutospores.
Saccardo
. .
.
.
.
26-15 X 20-12
22-17
44-26 x 26-17
Winter .
.
.
.
.
.
26-15 X 20-21
21-17
44-26x 26-17
Schröter
. .
.
. .
......
22-17
33-28 X 25-20
India
. .
.
. . 32-16 X 28-16
26-19 X 23-17
34-26 X 23-18
Winter notes that the uredo-and teleuto-spore pustules are long, covered by
epidermis, but this is not the case in India. In Simla we have also an example
of an imperfectly developed peridium in a Cæoma on Morus alba, which I have
included among the Cæomata in my "Descriptive List of the Simla Uredineæ."*
The European variety of P. Prenanthis, and the Cœoma Mori of Simla, are interest.
ing examples, therefore, of an intermediate and mostly vanished stage between
Aecidium and Cœoma.
II. Puccinia Prainiana, nov. sp.
Syn. Cœoma smilacis, Barclay.
A systematic description of this fungus will be found in Part IV of these
Memoirs. At the time that paper was written I conducted all my culture ex-
periments, with a view to observing the germination of spores, in hanging drops
of water, which necessarily implied a very restricted access of air, and therefore
of oxygen. Under these circumstances I never succeeded in obtaining any
germination of uredospores, and only an initial germination in æcidiospores,
whilst the teleutospores germinated in a peculiar way, the end of each promycelium
breaking up into three to four detached cells, each apparently representing a
sporidium. This peculiar germination of the teleutospores I took to be a new
type of normal germination, and I was supported in this view by observing exactly
the same kind of germination in the teleutospores of Uromyces Solidaginis, Niessl.
When placed under similar conditions, and by the observations of Kienitz-Gerloff.
on the teleutospores of Gymnosporangium clavareceforme. At the same time I
also noted that this peculiar sporidial development might be due to the unsuitable
media ( water and a decoction of Smilax leaves ) in which I aced the teleuto-
spores. Further study has taught me that this abnormal germination is abnormal
and that it was probably due to the restricted supply of air to the germinating
spores; for, if they be allowed to germinate in a freer atmosphere, e.g. in a watch
* Journal of the Asiatic Soc. of Bengal, Vol. LIX, Part II, No. 2,1890.
K2
Scientific Memoirs by
glass of water under á bell glass, as recommended by Plowright, they produce
regular sporidia in the usual way. Under these circumstances the contents of
the spore cells, which are orange red, wander into the discal ends of the promy-
celia, which then divide as usual, and produce four sporidia on four long and
stout sterigmata (fig. 4b). The sporidia are large, round to oval, orange red bodies,
measuring 22-10 X I2-8 μ , becoming readily detached, and germinating in the
usual way (fig. 4c). Secondary sporidia are sometimes formed,. measuring
14 X 8μ . (fig. 4d.)
Æcidio-and uredo-spores under similar conditions also germinate freely,
especially, the former, which throw out single long unbranched germ tubes, some-
times sinuous. The uredospores do not germinate quite so readily in water :
they emit a single simple tube from the middle of the spore, not through the
thickened end.
In my former paper I noted that I had been successful in only one of several
attempts to reproduce the aecidial stage by inoculation with teleutospores, and
that I did not consider one success sufficient to eatablish my argument. I there-
fore repeated these experiments in 1890. I made use, as usual, of twigs whose
ends had been cut under water, and upon the leaves of these I placed sporidia,
covering them thereafter with glass shades, and keeping the air within moist.
Under these circumstances the newly unfolded tender leaves (which alone are
open to attack) seldom survived long, and in several instances decayed before
any sign of attack appeared. But on the 22nd of April I inoculated some leaves,
which showed distinct initial attack on the 29th, but they died soon afterwards
without even producing spermogonia. I was more successful, however, in my
next experiment. On the 6th May I inoculated another twig and then put it in
a gardener's box where the air was more abundant, and not so moist. On the 13th
I noticed four distinct spots of attack, which soon became yellow and bore
numerous spermogonia. The experimental evidence is therefore now sufficient to
establish the autcecious nature of the parasite.
This fungus is apparently distinct from P. smilacis, Schwein, which has
short paraphyses among its uredospores (absent in the Simla species). The
uredospores are 21-27μ in diameter, against 46.5 X 31.7 in Simla, and the teleuto-
spores 42-36 X 21μ , against 70-50 x 14. Moreover, the American species is a
Hemipuccinia. In America an isolated aecidium on a distinct species of Smilax,
S. herbacea, is known (A. Smilacis, Schwein), but it is apparently not asso-
ciated with the Puccinia; its æcidiospores measure 22-18 X 18-15μ , against
52-36 X 28-16 in the Simla species.
This is doubtless, therefore, a new species, and I propose naming it Puccinia
Prainiana after my friend Dr. D. Prain, Curator of the Herbarium at the Royal
Botanic Garden, Calcutta, to whom I am indebted for Much valuable assis-
tance.
68
Medical Officers of the Army of India.
69
General Remarks.
As long as it was believed that the Cœomata were specially related to
the Melampsorœ, there were good grounds for separating such forms from the
Aecidieœ; but the time has now come to revise this basis of separation. The
idea of a special relationship with Melampsorœ, naturally sprung from Hartig's
and Rostrup's discoveries of the life histories of several Cœomata in 1880 and
1883, all of which were found to be related to Melampsorce. Thus Hartig, in
1880, found that Æ cidium columnare was related to Calyptospora (Melampsoræ)
Gœppertiana, and Rostrup, in 1883, that Cœoma Euonymi, C. Ribesii and C.
Mercurialis were respectively related to Melampsoræ farinosa, Pers., M. Hartigii,
and M. Tremulæ. Plowright could not, however, confirm the two former. Sub-
sequently other similar connection was established between C. Laricis and
M. Tremulæ (another species?) by Hartig in 1885, and between C. Mercurialis
and M. æcidioides by Plowright in 1888. Indeed, with the exception of Hartig's
M. Gœppertiana and M. populina, which Rathay states is generically related.
with Aec. Clematitis (in 1881), the life histories of every Melampsorce which has
been traced and found to include æcidial fructification have been found to be
associated with the æcidial forms known as Cæomata. I believe Rathay's case
has never been confirmed. There were therefore strong ground for believing
that all Cæomata were phases in the life histories of the Melampsoræ. Never-
theless most systematic writers, though adopting the presumed relationship, did
so in a hesitating manner, and referred to the necessity for further evidence, e.g.
Plowright and Schröter. Winter, on the other hand, in his definition of Melamp-
sorce says the Æ cidium is as with the Puccinia. In Saccardo's Sylloge Fun-
gorum the isolated aecidial forms without peridia are regarded as a subgenus of
Uredo.
The two cases of Rathay, and especially of Harting, referred to above show
that the Melampsoræ may include a typical cecidial stage, as distinguished
from Cæoma; and the occurrence of autæcious species of Puccinia, in which the
æcidial fructification is without any trace of pseudo-peridium, and therefore a true
Cæoma in the old sense is additional evidence that no necessary connection
exists between Melampsoræ and Cæoma.
Hence, as on the one hand, we have evidence of a Melampsoræ producing
an Æcidium, and on the other of a Puccinia producing a Cœoma, I think the
necessity for maintaining the latter genus no longer exists, and the genus might
therefore with advantage be reduced. The only essential difference between a
Cæoma and an Æcidium is the absence in the former of a peridium, though
Schröter also mentions a flatness of the spermogonia. The latter is an insignifi-
cant character, and while the spermogonia of the Cæoma on Smilax are large
and conical, there are numerous examples of small, flat and superficial spermogo-
nia in several species of Æcidium in Simla, and doubtless also elsewhere.
Description of Plate.
FIG. 1. Photograph, natural size, of leaf of Smila xaspera, showing teleutosporic stage.
"
" 2. Uredospore from Prenanthes, x 350.
„ 3. Teleutospore from Prenanthes, X 350.
„ 4a. Teleutospore from Smilax, showing places of exit of promycelia and swollen
stalk X 350.
b. Showing end of promycelium, with one Sporidium in situ , x 350.
c. Detached sporidia, one germinating, x 350.
d. Secondary sporidium, x 350.
„ 5. Ungerminated uredospore from Penanthis, X 350.
„ 6. Uredospore, with detached germ tube, x 240.
„ 7. Teleutospore from Lactuca.
PUCCINIA PRAINIANA AND P. PRENANTHIS.
22, San, India.—26-11-90.—350.
Litho., S. I. 0., Calcutta.