314 ME. P. H. GOSSE ON THE DKECIOIJS CHAEACTEE OP THE EOTIPEEA. 
It is manifest, however, that the animal which the German zoologist describes as a 
Notommata must be referred to my genus Asplanchna; and that its alliance with 
A. Brightwellii is still more intimate than is that of A. priodonta. Thus we have still 
no absolute proof that the dioecious character is not confined to a single genus. 
6. Dr. Letdig, however, conjectures, and supports his suggestion with many plausible 
reasons, that several animals, described and figured by EHEE^*BEEG as distinct species, 
may be really the males of other recognized forms. Thus Enteroplea hydatina he ven- 
tures to assign as the male of Hydatina senta, grounding his conclusions on the descrip- 
tions and figui’es of Eheenbeeg and Dujaedin. The close resemblance of Enterojylea to 
Hydatina, its smaller dimensions, and the absence of a manducatory apparatus, had been 
noticed by Eheenbeeg, who found the eggs which produced the animal, among those 
from which were evolved Hydatince. What Eheenbeeg described as an undeveloped 
ovary. Dr. Leydig considers to have been analogous to the sperm-bag of ]\D. Daletyiple ; 
in other words, a true testicle. This last interpretation is further confirmed by the 
figure given by Dujaedin ; in which, moreover, additional evidence is found, in the 
absence of a true alimentary canal, in the presence of certain ‘■'•touffes des granules ;pedi- 
cellees ” in the posterior part of the body (which Dr. Letdig interprets as “ masses 
of spermatozoids ”), and of “ un organ cilie entre les muscles de la queue,” which 
Dr. Leydig supposes to have been the excretory duct of the testicle, i. e. the penis. 
7. To these conclusions I entirely assent (perhaps with the exception of his interpre- 
tation of Dujaedin’s “ touffes pMicellees ”) ; and they are still further confirmed by the 
observations which I have presently to offer. 
8. For reasons of a similar character. Dr. Leydig presumes Hotommata granulans of 
Eheenbeeg to be the male of N. Brachionus, and Biglena granularis of Weisse to be the 
male of I). catellina. 
9. The first occasion on which I saw a male of this Class was on the 9th of August, 
1849, when, however, I was too inexperienced in the study of the Eotifeea to be awai'e 
of the true character of the animal which I was obsei”vdng. Among many specimens of 
Brachionus jyala, which I had just obtained from a pond near London, was one with 
seven or eight eggs excluded and attached to the posterior extremity of the lorica. One 
of these eggs was discharged from the ovary in my sight, so that I was sme of theh 
origin. When extruded, the ovum displayed a substance slightly granular, and almost 
colourless, except that a slight tinge of smoky black pervaded the whole. In an horn- 
or two this pellucid interior became turbid, and soon after Avas marked AAnth indistmct 
corrugations, which gradually acquhed more definiteness. The waves of the frontal cilia 
were next seen at one extremity of the egg, sometimes moAing transversely, sometimes 
longitudinally, but conveying, in either case, no accurate idea of the organs AAdiich pro- 
duced them. The vacant space occupied by these waves became larger, and presently 
the eye became visible, as an undefined pale red spot, near the middle of the egg. 
About the same time two or three amorphous masses of opake substance Avere seen near 
the posterior extremity. See Plate XV. fig. 1. 
