22 



human intestine, in which it grew up, bred, and, in the ordinary 

 course of things, died. 



The Rivalry between Parasitology and Zoology. 



Parasitology has now become a vast field of research 1 , 

 and the parasitic aspect of the threadworm at present over- 

 shadows to no small extent the concurrent labours of zoologists 

 proper. Parasitologists have grouped together animals pos- 

 sessing the habit of parasitism in common, though differing 

 greatly in their morphological characters 2 . It may be 

 anticipated, however, that zoologists will, in the near future, 

 re-assert themselves in the domain of threadworm research, 

 by emphasising the importance of its relationship with other 

 non- parasitic forms of life, from a purely systematic point 

 of view. And, through this, biological science is likely to be 

 the gainer 3 . 



demeure sur elles. Sous 1'influence 

 d'une alimentation surabondante 

 et d'une securite plus grande, 1'espece 

 de ces animaux prospera et 1'habi- 

 tude du parasitisme s'accrut chez 

 leurs descendants : ert meme temps, 

 leur caracteres se modifiaient plus 

 ou moins profondement par la 

 disparition de tels organes de 

 relation devenus inutiles a un 

 animal fixe, par le developpement 

 de 1'appareil de fixation, par des 

 modifications dans la taille, etc." 

 (MoNiEZ, R., Les Parasites de 

 rilomme, Paris, 1889, pp. ], 2.) 



1 Parasitologists are constantly 

 adding to the number of parasites 

 known. Thirty years ago no less than 

 38 genera of parasites infesting the 

 human intestine were described : 

 " Wir kennen heute nach mehr 

 oder minder genauen Angaben 

 38 Arten von menschlichen Einge- 

 weidewiirmern. . . . Die Rund- 

 wiirmer oder Nematoden sind in 

 Hinsicht auf Gattungen und Arten 

 am reichsten vertreten. Wir zah- 

 len im Ganzen beim Menschen 16 

 Arten auf 9 Gattungen vertheilt." 



(VoGT, C., Die Herkunft der Einge- 

 weidewuermer des Menschen, Basel, 

 1878, pp. 6 and 11.) 



2 " M. Dumeril fait une classe 

 particuliere des vers intestinaux ; 

 il leur donne le nom d'helminthes." 

 (TuRPiN, V., Dissertation sur les 

 vers des intestins, Paris, 1834, p. 6.) 



3 The following represents the 

 most recent scientific classification of 

 Oxyuris Vermicularis ; but the ac- 

 cepted views on its zoological posi- 

 tion are constantly fluctuating : 



SUB-KINGDOM : Metazoa. 



BRANCH : 

 GRADE : 

 SUB-GRADE 

 CLASS : 

 ORDER : 

 (SUB-ORDER 

 FAMILY : 

 GENUS : 

 SPECIES : 

 (SHIPLEY, A. E., 



Enterozoa. 

 Coelomocoela. 

 Invertebrata. 

 Nemathelmintha. 

 Nematoda. 

 Meromyarii.) 

 Ascaridae. 

 Oxyuris. 

 Vermicularis. 

 The Cambridge 



Natural History, London, 1896, 

 vol. ii., pp. 123etseq., and LANKES- 

 TER, E. R., A Treatise on Zoology, 



London, 

 and 2.) 



1900, part ii., pp. 



