ASCARIDIA LINEATA, A PARASITE OF CHICKENS IN 
THE UNITED STATES 1 
By Benjamin Schwartz 
Zoological Division , Bureau of Animal Industry, United States Department of 
Agriculture 
INTRODUCTION 
Heretofore it has been assumed that 
the large intestinal roundworm of 
chickens in the United States is As¬ 
caridia perspicillum, a species described 
from the intestine of turkeys by Rudol- 
phi in 1803 {12 ). 2 A recent study by 
the present writer of specimens of 
Ascaridia collected at various times 
from the intestine of chickens, in and 
around Washington, D. C., in New 
Jersey, Kansas, and in several other 
localities, has shown that the species 
in question does not conform to the 
description of A. perspicillum as given 
by various writers, but conforms in 
practically all respects to the descrip¬ 
tion of another species, namely, A. 
lineata, which was described by Schnei¬ 
der in 1866 (13). 
These two species have undoubtedly 
been confused in the past, partly owing 
to their close relationship, and partly 
because the tendency of most workers 
who are not systematists is to make 
host determinations of parasites. The 
fact that A. perspicillum is an earlier 
described species and that its type 
locality is Europe is probably largely 
responsible for the importance that has 
been assigned to it in textbooks on 
parasitology, whereas A. lineata, which 
was originally described from Brazil, 
has received but secondary considera¬ 
tion in the widely used textbooks on 
parasitology, nearly all of which have 
been written by European workers. 
As will be presently shown, A. lineata is 
not only more prevalent then A. per¬ 
spicillum in the United States and in all 
probability in other parts of the world, 
but is also possibly the only species of 
Ascaridia parasitic in chickens in this 
country, the occurrence of A. perspicil¬ 
lum in American chickens not yet hav¬ 
ing been definitely established.^ 
ASCARIDIA PERSPICILLUM (RU- 
DOLPHI, 1803) 
Rudolphi’s description of Ascaris 
perspicillum is based on immature fe¬ 
male specimens from the turkey, and, 
in common with specific diagnoses of a 
century ago, contains little that is of 
diagnostic value. According to Dujar- 
din (3) A. perspicillum of Rudolphi is 
apparently identical with Fusaria in- 
flexa of Zeder. Dujardin (3) states that 
the entries in the catalogue of the 
Vienna Museum, whose helminthologi¬ 
cal collections were studied by Rudolphi, 
contain no reference to A. inflexa from 
chickens, this species being recorded 
only from ducks. Dujardin also states 
that the catalogue in question contains 
but a single entry of A. perspicillum 
from the turkey. 
Schneider (13), in his extensive mon¬ 
ograph on nematodes, states that he 
examined one male and one female 
specimen of Heterakis perspicillum and 
found them to be identical with H. in¬ 
flexa, of which he also examined speci¬ 
mens. In both cases the material ex¬ 
amined appears to have been material 
studied by Rudolphi. Although 
Schneider was unable to make out the 
structure of the lips in the specimens 
labeled Ascaris perspicillum, he had no 
difficulty in making out the papillae 
on the tail of the male, which he foiind 
to correspond to those of A. inflexa. 
Since the papillae on the tail of the male 
are commonly regarded as the most 
important specific characters in the 
suckered roundworms (Heterakidae), 
it may be taken for granted that Schnei¬ 
der was correct in regarding A. perspi¬ 
cillum and A. inflexa as identical. 
Schneider figures 9 pairs of papillae 
on the tail of the male of Heterakis in¬ 
flexa (fig. 1), arranged as follows: 3 
pairs of ventral papillae arranged in a 
row on each side of the sucker, the most 
cephalad papillae being anterior to, and 
the third, or most caudal pair, being 
posterior to the sucker, whereas the 
middle pair corresponds in position ap¬ 
proximately to the equator of the 
sucker. The next group consists of 4 
pairs of papillae, of which 3 pairs are 
lateral and 1 pair is ventral, and finally, 
there are 2 pairs of lateral papillae near 
the tip of the tail. 
1 Received for publication June 30,1924; issued June, 1925. 
2 Reference is made by number (italic) to “ Literature cited,” p. 772. 
Journal of Agricultural Research, 
Washington, D. C. 
( 763 ) 
Vol.XXX, No. 8 
Apr. 15, 1925 
Key No. A-89 
