GOEDIIDJl. 59 



be seen by the passage quoted below.* The muscular layer 

 consists of longitudinal and radiating fibres intimately blended 

 together, forming a tube cJiarnu, which is lined internally by a soft 

 parenchymatous mass, common to Nematodes generally. In this 

 mass Dujardin recognized another canal, which he regarded as a 

 secreting organ concerned in the production of certain pecuhar 

 bodies termed oviferous capsules ; but in forming this opinion he 

 was doubtless in error. At all events, the interior of the canal is 

 described by him as being lined by " a large ovarian band or lon- 

 gitudinal placenta;" and to tliis band numerous oviferous spherical 

 capsules are connected by means of a double row of funiculi. Each 

 capsule contains within it a single ovum, which, when mature, 

 makes its escape by the natural separation of the two halves or 

 valves of the capsule. At the time of embryonic maturation the 

 funiculi or chalazge become detached from the longitudinal band, 

 their free ends splitting up, as it were, into numerous filaments 

 or brush-hke processes. These structures which, in some respects, 

 may be regarded as unique, have been since described by Meissner, 

 Yan Beneden, etc., and have been shown by them to be normally 

 developed within the ovarian tube ; the last-named authority did 

 not observe any of them to be connected to the rachis or longi- 

 tudinal placenta described by Dujardin. 



Development. — In regard to the antecedent and other changes 

 connected with the history of the development of the ovum, it has 

 been pointed out by Meissner that in Mermis albicans the first re- 

 productive changes consist in the formation of germ cells within 

 the narrow coecal extremity of the ovarian tube. This, of course, 

 is the first essential step of the process in all the Nematoda ; but 

 important differences of detail are found to characterise ovular 



t " Ces cordons en raison de leur inegalite ne me seniblent nuUemeut pouvoir eti'c 

 assimiles a des vaisseaux ou a des nerfs ; s'il fallait faire quelque conjecture sur leur 

 nature et sur leur role physiologique, j'aimerais niieux supposer qu'ils servent a 

 I'acconiplissement d'une sorte de respiration branchiale, executee dans I'iuterieur de la 

 cavite et a la face interne du tegument, comme cela a lieu cliez les Systolides et chez 

 les Nai's." 



