822 The American Naturalist. 
Myxine : a Protandric Hermaphrodite.— True males are ex- 
tremely rare in Myxine. Out of several hundred specimens examined, 
I have recognized only very few males, and even those were unripe. 
The male organs are usually easy to distinguish from the ovaries ; they 
are generally lobate, have a milky whitish color — especially in some- 
what mature state — whilst the ovaries are more translucent. Small 
nodules are visible in both, but the nodules of the testes {i.e., the sper- 
ma-follicles) are smaller and whiter than the nodules of the ovaries 
{i.e., the young ova). In quite an early stage there is, however, little 
difference between testes and ovaries : they have the same translucent 
appearance, and are developed only on the right side of the straight 
intestine. As stated by previous authors, the testis as well as the 
ovary is secured by a membrane (mesorchium mesoarium) to the 
mesentery at the point where it is fastened to the intestine. 
The minute structure of the male organs will subsecjuently be de- 
scribed, but we will first examine their occurrence and extension. A 
feature which attracted my attention on the first superficial examination 
of the testes of the few true males I had been able to recognize was, 
that the testes were usually much more developed and prominent at 
their posterior than at their anterior end. The reason of that I could 
for some time not discover ; it will subsequently be seen that I have, 
perhaps, traced the cause. 
But why do the males occur so extremely seldom ? Before we attempt 
to solve this question, let us discuss the generative organs of the large 
number of Myxine which were recognized not to be true males. On 
opening large specimens of Myxine, we generally find well developed 
ova in their sexual organs. If we, however, take smaller specimens of 
28 to 32 cm. in length, and examine their sexual organs, we generally 
find that the anterior portion is but slightly prominent, and contains 
very small and young ova, whilst the posterior portion is often very 
broad and prominent, is lobate, and has a distinct whitish color along 
its margin, and has, in all respects, the appearance we would expect to 
find in a testis ; and this it really is. If we take a piece of the margin 
of this portion of the generative organ, tease it, and examine it in the 
fresh state under the microscope, we generally find abundance of 
spermatozoa in various stages of development There can thus be no 
doubt then that that portion of the generative organ is a real male 
organ. It is, indeed, strange that Cunningham has so little succeeded 
in finding spermataozoa. Those young specimens of 28-32 cm. in 
length are consequently hermaphrodites, with quite immature ovaries 
