44 



denied by nearly every writer since then. Much stress was 

 originally laid upon the precise appearance of the alar cutic-' 

 ular expansions, and probably much of the confusion has 

 arisen from the apparent fact that these are by no means con- 

 stant in size and shape, and seem to be at times entirely 

 absent. That there are several closely allied species, and that 

 there may be a number of more or less distinct variations, can 

 scarcely be denied, and until breeding experiments are added 

 to the existing morphological observations it is not likely 

 that the difficulties of classification will be entirely removed. 



To illustrate the confused status of the question, these 

 outlined descriptions may be here quoted. Schneider 

 (Nematoden, p. 39; PI. I, Fig. 5), accepting Rudolphi's 

 specific name, Ascaris leptoptera, but declaring that his 

 original specimens were but Ascaris canis (Werner), describes, 

 from material including several hundred specimens from a 

 lion born in London and examined after death at nineteen 

 months of age in Berlin, a parasite having the following 

 characteristics: Females, 65 mm. long; males, 46 mm. long. 

 Lips equal, digitate, with rather pointed anterior margin 

 and broader base. Denticulation poorly developed and 

 inconspicuous, only showing along the lateral borders. Lobes 

 of pulpa of dorsal lip long, undivided. Lateral alar mem- 

 branes extend from head 4 mm. posteriorly, rounded at 

 posterior termination. The head, even in the youngest 

 examples, is deeply retracted between the salient cuticular 

 expansions. Vulva 25 mm. from anterior end of worm. 

 Shell of ovum thick, unmarked or only with irregular, 

 trabecular reticulation. Tail of male lancet-shaped, slightly 

 broadened, and with the ventral side flattened. Thirty- 

 five pairs of papillae, six postanal, the terminal and adjacent 

 ones with conical base; the rest all raised, with pointed tips; 

 all in uniform row. 



Chatin (Mem. de la Soc. de Biol., 1877, p. 266) records 

 from a lion a number of ascarides without alar cuticular 

 expansions, buccal lobes deeply divided, straight esophagus 



