1879. | The Breeding Habits of the Eel. 29 
eel. It appears that Carlo Mundini first discovered the ovary of 
the eel in May, 1777; this was confirmed by Rathke, who de- 
scribed the eggs. Siebold (1863) states that eels may repro- 
duce by parthenogenesis, or are hermaphrodite. In 1872 Ercolani 
claims to have found spermatozoa in eels, but Syrski is positive 
that he mistook them for “ the molecular movement of the gran- 
ules found so frequently in the tissues of the animal body.” 
Whether Ercolani was right we have not at present the means of 
ascertaining, but think it more probable he was right than his 
critic, Syrski. In the same year (1872), Crivelli and Maggi, of 
Pavia, claim to have discovered, and have figured the spermato- 
zoa. This memoir we have not yet seen. Syrski does not seem 
to endorse their statements. In 1874 Prof. Minter stated that 
he found ovaries in about 3000 eels examined for that purpose, 
but he never found a male eel, z. e., a milter. He therefore admits 
that eels are reproduced by parthenogenesis, z. e., from non- 
fecundated eggs, and remarks, “In all probability is eggs are 
deposited at the bottom of the Baltic sea from the middle of 
March to the middle of April, and the young eels, one-half to 
two inches long, born from such eggs, migrate into fresh water 
about the beginning of May.” 
Syrski then describes and figures the ovaries and “ testes,” as 
he regards them, of the eel. The “eggs” figured as such by him 
are certainly not such, but are the male sperm-cysts,.and he has 
thus entirely mistaken the sex of the eel. He does not figure 
or describe the true ovarian egg or the ripe egg, which are, in the 
American eel at least, wholly different in their mode of develop- 
ment from Syrski’s so-called eggs, and so different that we doubt 
not but that his females were really the males of the European 
species. He figures and describes a portion of what he regards 
` as a testis, but gives no description of the mother-cells, sperm- 
cysts and spermatozoa; of the latter he says nothing. It is evi- | 
dent that this observer has been throughout mistaken, and has 
thrown little light on the subject. 
To be sure that I have not been over confident in regard to this _ 
matter, after reading Syrski’s article I have dissected another living — 
male, and found the mother-cells, sperm-cysts and the exceed- 
ingly minute, free-moving spermatozoa, which were more abun- __ 
dant than usual in small males. I also reéxamined the ovary of | 
a female not in spawn, and demonstrated them to Mr. J. S. Kings- a 
