OOGENESIS AND EARLY EMBRYOLOGY ASCARIS 529 



variety of names, no two workers using the same system of 

 nomenclature. In 1872 an attempt was made to simplify the 

 confusion by uniting all the various forms in one species, Ascaris 

 mystax, the parasites of the different hosts being known as sub- 

 species, and designated by terms indicative of their hosts, — for 

 example, A. mystax, sp. canis, — or by some peculiarity of the 

 external appearance of the worm — for example, A. mystax, sp. 

 marginata. (For a complete list of these species and sub- 

 species, see Glaue, '09.) The activities of Rudolphi and others 

 in the next twenty years produced such a number of sub-species 

 that Zeder (1803) proposed that the nomenclature be so modi- 

 fied as to restrict the use of the name Ascaris mystax to the in- 

 testinal parasites of the dog and the cat, the parasites of the other 

 hosts formerly included in this species being established as dis- 

 tinct species. Rudolphi, discarding the name A. mystax, called 

 the type which he believed to be peculiar to the Canidae, and 

 perhaps the Felidae, by the name A. marginata. Schneider, in 

 his ''Monographie der Nematoden" ('66), returned to the nom- 

 enclature of Zeder, but Werner ('85) advocated the term A. 

 canis, instead of Zeder's A. mystax, for the ascarids of the dog, 

 the cat (A. felis Goeze), and their near relatives, the bears, 

 wolves, foxes, lions and panthers. 



It was owing to this confounding of distinct species, that the 

 morphological and cytological results of the early cytologists 

 when working on the intestinal nematodes of either the dog or 

 the cat were often at variance. Regarding these several scien- 

 tific names as synonomous, they unhesitatingly identified their 

 species with that worked on by some one else, although their 

 results varied considerably. 



No attempt will be made to give here anything more than a 

 very brief outline of the contents of any of the works cited, de- 

 tailed reference to them being made throughout the present 

 paper wherever the citations are pertinent. 



Nelson ('52), Bischoff ('55), Meissner ('55), Thompson ('56), 

 Claparede ('58), and Munk ('58) all worked with material par- 

 asitic in dogs and followed Zeder in calling the parasites Ascaris 

 mystax. All these men worked on the sexual organs from an 



JOURNAL OF MORPHOLOGY, VOL. 30, NO. 2 



