91
SECTION I.
HISTORICAL REFERENCES.
Gros * observed minute worms (vermicules) in the blood of a field-mouse (mulót) which were so
numerous as to cause the blood to present an animated appearance; and that the blood of the mole
was often found to be in a similar condition. The vermicules were barely visible when magnified 400
diameters.
Chaussat † observed on many occasions in the blood of the black rat (Mus rattus, Lin.) microscopic
animalcules having the form of Filariæ; their movements were very rapid.
These parasites were seldom if ever observed in the blood of young rats, but were almost always seen
in adults.
Chaussat appeared to consider them to be Nematodes, but we do not doubt that they are very
analogous to, if not identical with, the organisms in question ; the same remark is applicable to those
hæmatozoa mentioned by Gros.
‡ Butschli "found a flagellated parasite which he has often observed in the intestinal canal of a
free nematode (Trilobus gracilis).
He refrains from giving it a name owing to the uncertainty which
exists with regard to organisms of this kind. He generally found them in large numbers, often form-
ing stellate colonies owing to their being attached by their non-flagellated ends. They readily became
detached and then presented a somewhat spindle-shaped body, about .011 m.m. in length and with a
somewhat thick flagellum about double this length, so that the total length of the protozoon would be
.033 m.m., something more than half of the length of the flagellated organism found in the rat's blood.
Near the base of the flagellum of Butschli's protozoon a contractile vacuole could be distinguished."
When Dr. T. R. Lewis § was detailed to make investigations into the etiology of Spirillum or
Bombay fever in July 1877, he had occasion to examine the blood of a considerable number of animals.
He then detected organisms in the blood of the rat which he took to be vibrios or spirilla. On microsco-
pical examination the blood "seemed to quiver with life." Two species of rats harboured these para-
sites Mus decumanus and Mus rufescens, but although Lewis examined the blood of a large number of
mice, he never detected organisms nor did he see them in any animals other than rats.
He found the organism present in rats examined in Calcutta and also at Simla in the Himalayas at
an elevation of 7,500 feet. The animals thus affected were kept in cages for weeks by him and they
remained to all appearance in a state of perfect health. At one time Lewis was inclined to think that
the organisms might be Spermatozoa of some parasite hidden in the tissues of the rat, as he had ob-
served several years previously Spermatozoids very much resembling the hæmatozoon escaping from
the reproductive pore of a segment of tænia obtained from that animal.
At a later date, 1880, when Evans discovered the presence of organisms in the blood of horses and
camels suffering from Surra in the Punjab, and further found that the disease was capable of repro-
duction by inoculation in the horse and dog, Lewis satisfied himself that the parasite in the dog was
identical with that in the rat.
With regard to the health of the rats in which these flagellated organisms were detected, Lewis
says : "There was nothing to suggest in any way that they were less healthy than others not so affected,
and I have repeatedly kept rats for a considerable time for the purpose of observing whether any spe-
cial symptoms would be manifested suggestive of the existence of such organisms in the circulation.
It frequently happened that the rats caught in a particular room would be affected, whereas the blood
of rats in another part of the building would not contain them.''
"They were pale, translucent beings, without any trace of visible structure or granularity; but as
their movements were so rapid, exact information as to their microscopical character could not be ascer-
tained at the time. The slides were therefore placed under a bell glass until these should diminish."
On the following morning the activity of the filaments was much less. Their movements were
more restricted and more undulatory in character, and the blood corpuscles having become somewhat
agglutinated, had apparently squeezed out the organisms, so that the latter occupied the serum areas
of the preparations. It was eventually observed that this movement was due to the existence of a
very long and exceedingly fine flagellum, apparently a posterior flagellum, as the organisms seemed
generally to move with the thickened end forwards—the flagellum being seen following it, and lashing
the fluid during the movement, it remained in focus. I have not been able to detect any flagellum at
the opposite end. They may sometimes be kept alive for two or three days, but generally the greater
portion will have died within 12 to 24 hours : and not only have died, but also disappeared from view,
* Gros.—Referred to by Bastian,"Beginnings of Life." Vol. II. Pg. 338, 1872.
† Chaussat.—Des hæmatozoaires, Thése. 1850, Paris ; also
Dict: Encyclop : des : Science : Med Dechambre et Lereboullet.
‡ Butschli.—Zeitschr fur Wissentsch Zoologie Band XXX. Heft 2 Taf XI, fig. 9 Jan. 1878.
"Microscopic Organisms in Blood of Man and Animals."
§ Lewis, T. R.—Appendix 14th, Annual Report of Sanitary Commissioner with the Government of India, 1878.
"Quarterly Journal of Micros : Science,"Vol. LXXIII, page 109, 1879.
"Further Observations on Flagellated Organisms in the Blood of Animals," 1884.