THE ANATOMY OF ONOHOLAIMUS VULGARIS, BAST. 101 



The Anatomy of Oncholaimus vulgaris, Bast., 

 with Notes on two Parasitic Nematodes. 



By 



F. H. Stewart, M.A., B.Sc, M.B., 



Lieut. Indian Medical Service. 



With Plates 7—9. 



I BEGAN this work witli the intention of trying to ascertain 

 if any light conld be thrown on the comparative morphology 

 of the coelom and JSTephridia by the study of Nematodes. The 

 uncertainty as to the true nature of the body-spaces in this 

 class is well known. No one has been sufficiently daring to 

 identify any space in Nematodes with the coelom. The space 

 between the body wall and the gut is generally admitted to 

 be a schizoele. 



Ray Lankester (11, p. 9) writes: "In some few groups of 

 Coelomocoela the coeloms have remained small^ and limited to 

 the character of simple gouocoels. This seems to be the case 

 in the Nemertina, the Planarians, and other Platyhelmia." 

 The Nematodes are not meutioned, since nothing is dehnitely 

 known in regard to them. 



Thanks largely to the work of Jagerskiold (9), we know 

 that the excretory organs of Nematodes are unicellular, with 

 intra-cellular canals, and, physiologically at least, interchange- 

 able with skin glands, but they have not yet been homologised 

 with Nephridia. Ray Lankester, in the same article (11, 

 p. 14), writes: "True Nephridia are only found in the 



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