50 J. T. CUNNINGHAM. 



to the yolk of the egg ; the substance within the testicular 

 vesicles consists of granules of various sizes, but all smaller than 

 the yolk granules. Spermatozoa at the time when the Myxine 

 were examined in the fresh condition (August) were not present ; 

 they are apparently only to be observed at the breeding season. 

 The most important difference between the testicular vesicles 

 (hodenblaschen = korner, mentioned above) and the eggs seems 

 to lie in the fact that in the former the germinal vesicle is 

 wanting. 



'' The eggs are, when small, round ; later they become much 

 elongated, and the ripe ones are very large. I have seen 

 them in specimens preserved in spirit as long as 6'" (13 mm.). 

 At the time when I examined the Myxine alive the eggs were 

 not large. In all young eggs, besides the yolk granules, is 

 seen the germinal vesicle, which is very distinct; it contains, 

 besides smaller granula, two or three cells with nuclei which 

 form the germinal spot. When the eggs have become elon- 

 gated the germinal vesicle lies always at one of the thin ends 

 of the eggs. The yolk granules are differently constructed to 

 the granula of the testicular vesicles ; the granula of the latter 

 are much smaller and round ; the yolk granules are, on the 

 contrary, ellipsoidal, and quite similar to the yolk granules of 

 the Elasmobranchs, i.e. they have transverse lines on the sur- 

 face which indicate a differentiation of substance and recall 

 the amylon bodies. These lines are present in the fresh con- 

 dition, as in Sharks and Rays.'^ 



The following figures are given : 



Taf. i, fig. 1. — The right side of the abdominal cavity of a 

 male Myxine ; the testis exposed ; natural size. 



Taf. ii, fig. 3. — Testicular vesicles in the mesorchium of 

 Bdellostoma Forsteri, natural size; the vesicles are here 

 large and distinct, and project from the edge of the mesorchium ; 

 in the former figure the separate vesicles cannot be distin- 

 guished. 



Taf. ii, fig. 6. — Young round egg of Myxine fresh magni- 

 fied. 



Taf. ii, fig. 7. — Young egg slightly elongated. 



