326
Nematode Parasites from Domesticated Animals
caudal extremity, the third pair a little larger and anterior to the first two pairs
the fourth pair larger and much anterior to the third, the fifth and sixth pairs,
about the same size as the fourth and a little posterior to cloaca. Workers
seem to differ in their views regarding the number of these postanal papillæ.
Cram [1927] and Neveu-Lemaire [1936] record five pairs, whereas, Baylis
[1929], Monnig [1934], Sprehn [1932], and Tubangui [1927] record six pairs.
The present material shows six pairs but, unlike that of Tubangui, the last two
pairs of postanal papillæ near the tip of the tail are smaller than other papillæ.
Spicules markedly unequal and dissimilar—left slender, 1.25-1.5 long, ending
in. a chisel-shaped tip, right broad, 0.2-0.24 long with the shape of a chopping
knife. Tubangui records the length of right and left spicules as 0.5 and 1.82
respectively, according to which the left appears to be less than four times as
long as the right, whereas Cram records the left spicule six times as long as the
right. The present material shows a size which approximates to Cram's
measurements, though the maximum length of the right spicule shows a length
less than half that of Tubangui's material. It may however be pointed out
here that though Tubangui records 0.5 as length of right spicule, his diagram
(Fig. 15 B) of tail end of male shows the spicule length as approximately 0. 2,
a measurement that corroborates with the present material.
Female.—Body 11.2-25.6 long and 0.36-0.5 in maximum diameter.
Pharynx 0.21-0.28 long. Anterior portion of oesophagus 0.71-1.16, and post-
erior portion 2.65-4 long. Nerve-ring 0.3-0.47 from anterior end. Vulva
lying posterior to middle of body 6.2-14.2 from anterior end, leading into a
long muscular vagina which opens into the ' common trunk' of the uterus,
which after traversing a short distance posteriorly joins the two connecting
tubules of the opposed uteri. In young forms the vagina runs straight back-
wards but in older forms it first passses posteriorly, then anteriorly and then
again posteriorly like the shape of laterally placed S ; its connection with the
' common trunk' of the uterus is difficult to ascertain owing to the profuse
development of uterus and eggs contained therein.
Tail 0.34-0.53
long, gradually attenuated and ending in a small spike-like termination.
Eggs 0.038-0.042×0.022-0.025, with smooth thick shells enclosing a coiled
embryo occupying almost the entire space within the shell. [Tubangui
(1927) records the dimensions as 0.043-0.045×0.024-0.025.]
Life-history.—Large numbers of eggs are deposited by the female in the
gizzard and are subsequently passed out of the body with the droppings.
If eggs are ingested by a suitable intermediate host the larvae develop to the
infective stage in about 19-25 days. Cram [1931] and Cuvillier [1933] report
a number of grasshoppers serving as intermediate hosts in the United
States but a recent investigation by Alicata [1937] in Hawaii has shown that
in addition to the former, the ' sand-hopper ' (Orchestia platensis), flour beetles
(Tribolium castaneum, Tenebroides nana and Carpophilus dimidatus), weevils
(Oxydema fusiforme and Sitophilus oryzae) and other beetles found around poul-
try manure are also carriers of infection. Fowls become infected by ingesting