454 GENERAL HISTORY OE THE INFUSORIA. 



lateral muscles. Connected with the testis is a well-defined intromittent 

 organ, and a conspicuous passage or opening for its extension from the body 

 of the animal. In the opposite lower angle are three small, irregularly- 

 foi-med, kidney- shaped bodies, connected with an angular lobe or muscle 

 lying beneath them. The male is also furnished with the delicate mem- 

 branous plicated bag, and rudiments of the curled tubular structure, found 

 in the female." 



Besides determining the dioecious character of this Rotifer, Mr. Brightwell 

 was also enabled to repeatedly verify the occurrence of an actual coitus occur- 

 ring between the sexes, and enduring the greater part of a minute. 



The male of the allied species Asplanclina priodonta was described by Mr. 

 Gosse. As the description supplies additional particulars concerning the 

 organization, we extract it entu^e. 



Having isolated an adult female, in which the developing yoimg seemed 

 different from the ordinaiy embiyos, he at length had the satisfaction of 

 seeing two males born. '' Another was produced the same evening from 

 another parent, likewise under my eye." 



" The length of these specimens (XXXVI. 7, 8) (male) was yy^th of an 

 inch (that of the females was -^t^ to y^^d of an inch). They had a general 

 agreement in outline with the female. But the outlet corresponding to the 

 vagina was at the veiy bottom of the ventral side (XXXVI. 7, 8 h), which 

 ran down to a point, while the dorsal side was rounded off. At the base of 

 this tube was a globular sperm-sac, with a short thick penis in front, the 

 whole nearly surrounded by a delicate glandular mass. The place of the 

 stomach was occupied by a long sac, having a slender neck originating from the 

 fore part of the head mass, and at the bottom broadly attached to the sperm-bag. 

 This whole organ was filled with minute granular matter, except three or four 

 clear globular bladders ; the sperm-bag showed a structure very similar. 



" The principal muscles agreed with those of the female. The tortuous 

 threads, and their plexuses, were represented by two thickened glandular 

 bodies, extending from the head mass to the foliaceous substance siuTounding 

 the sperm bag .... The three eyes were present, situated as in the female, 

 but no trace of jaws was discernible, even on pressure, nor any crop, nor 

 true stomach. These animals were very active, swimming rapidly about, and 

 scarcely still an instant. On one or two occasions, I observed one of the 

 males with a slender process protruded to a considerable length from the 

 sexual orifice, and adhering to the glass by its tip, moving round on it as on 

 a pivot." 



Leydig admits the bisexual or dioecious nature of the Rotatoria as a general 

 fact ; and although, he says, his studies have been diverted from special re- 

 searches on this matter, yet, from the descriptions and representations of 

 others, he believes he can detect several male forms arranged in the class as 

 distinct species. 



Of the male of a new species, which he calls Notommata Sieholdii, but 

 which is equally a member of the genus As^lcmchna with " the supposed new 

 Notommata " of BrightweU, he has given an elaborate description and draw- 

 ings. He remarks that in all details of organization it agrees with Mr. 

 Dalrymple's account, but, unlike the English species, differs considerably in 

 figure from the female, especially by the presence of four pointed arms 

 (XXXVII. 29). He remarks that '' the so-called " sperm-hag of Dalrymple 

 is the testicle, and what that author terms the " penis " is its duct. The 

 figures he gives of the seminal corpuscles are not altogether distinct, although 

 the resemblance between them and those of Notommata Sicholdii are unmis- 

 takeable. However, I must point out an error into which Dalrymple has 



