Apr. 15, 1925 
Ascaridia lineata, a Parasite of Chickens 
769 
second lateral papilla, but the location 
of the last ventral papilla is rather 
variable, being anterior to the last 
lateral papilla in certain specimens and 
posterior to it in other specimens. Not 
infrequently the arrangement of the 
papillae on the two sides of the bursa 
is asymmetrical (fig. 8). The position 
of the first lateral papilla with respect 
to the anus is also somewhat variable, 
being located either slightly anterior 
to, on a level with, or rarely somewhat 
posterior to the anus (figs. 4 to 13). 
Fig. 14 — Anteria end of Ascaridia lineata (original). 
e. p., excretory pore; n.r., nerve ring; oes., oe¬ 
sophagus. 
Spicules. —A considerable range of 
variation exists as regards the length 
of the spicules in Ascaridia lineata. 
According to Travassos (16), the spic¬ 
ules are 1.4 mm. long. According to 
Lane (5), they are 2 mm. long. Von 
Linstow (8) states that the spicules of 
Heterakis inflexa (misidentification of 
Ascaridia lineata) are 1.9 mm. long. 
Immature specimens from the chicken 
and goose from Tonkin, 1.8 mm. long, 
showed a range in spicule variation 
from 0.53 to 0.57 mm. in length. Some¬ 
what larger specimens from chickens 
had spicules measuring from 0.7 to 0.8 
mm. Spicules from not quite fully 
grown specimens from chickens in the 
Philippines varied from 0.9 to 1.3 mm. 
in length. Mature specimens from 
chickens from Tonkin showed a varia¬ 
tion in the length of the spicules from 
1.6 to 2.4 mm. Specimens from the 
United States showed a similar varia¬ 
tion in the size of the spicules, the 
youngest immature forms measured 
having spicules 0.6 mm. long, whereas 
large mature forms had spicules some¬ 
what in excess of 2 mm. 
In view of the specific importance 
that is commonly attributed to the size 
of the spicules in nematodes, the rather 
wide range of size variation noted in 
this species is worthy of emphasis. 
Sucker. —The size of the sucker as 
given by Lane is 0.2 mm. in diameter, 
agreeing closely with that of Travassos 
and Boulenger (so far as can be judged 
from the latter’s figure for which a 
scale is given). The maximum diam¬ 
eter of the sucker as observed by the 
present writer was 0.25 mm. and the 
minimum diameter in very young speci¬ 
mens was somewhat less than Oil 4 mm 
Additional variations were observed 
as regards the distance of the nerve 
ring and excretory pore from the cepha¬ 
lic extremity, the length of that portion 
of the vagina that extends cephalad, 
and the length of the tail in both sexes. 
The most conspicuous of these varia¬ 
tions are given below: According to 
Lane (5), the vagina runs cephalad for 
a distance of about 1 mm. before it 
turns caudad. In very young forms 
the writer found that the vagina runs 
cephalad for a distance of only 475 n 
(fig. 15), while in somewhat larger speci¬ 
mens that distance was found to be 
670 fi. In mature specimens the cepha¬ 
lad portion of the vagina was found to 
be somewhat longer than that given by 
Lane. The tail of the male in fully 
grown specimens was found to be 0.7 
mm., as compared with 0.5 mm. given 
by Lane, with a decrease in size in 
smaller specimens. The distances of 
the excretory pore and nerve ring from 
the cephalic extremity were found to be 
somewhat greater than those given by 
Lane in fully grown specimens, but con¬ 
siderably shorter in immature speci¬ 
mens (fig. 14). 
The position of the vulva is near the 
equator according to Lane (5), which 
corresponds to the observations of the 
present writer. According to Travas¬ 
sos (16) it is in the first third of the 
body. The size of the eggs, which are 
thick shelled, the shell being smooth, is 
