1879. | The Breeding Habits of the Eel. as 
cence into the body cavity,and pass out through a funnel-shaped 
fold of the peritoneum by a single small pore or opening identi- 
cal in form and situation (just behind the anus) in each sex. 
There are not two openings, as has been stated by some authors. 
The testis does not differ in form and appearance from the ovary 
when the female is not in spawn, at least we could find no differ- 
ences except that it is rather thinner. Both the right testis and 
ovary extend, in individuals about seventeen inches long, from 
about an inch and a quarter behind the vent, to near the dia- 
phragm; extending on the right side to half way between the 
anterior end of the gall bladder and the diaphragm, while both 
the left testis and ovary are shorter than the right, ending an inch 
behind the diaphragm. 
Microscopically examined the ovarian eggs lie in rows, with the 
stroma or tissue of fat cells between them. In the testis the sper- 
matozoa are developed in sperm cysts, or “ mother cells,” much 
smaller than the ovarian egg (one-sixth to one-fifth mm). The 
mother cells contain a nucleus about one-third the diameter of the 
mother cell ; in the nucleus is a dusky nucleolus about one-half 
the diameter of the nucleus. The sperm-cells are developed in the 
nucleus, They are nucleated, the nucleus large, and they (the 
sperm-cells) vary from ygdyp tO sọpv inch in diameter. The sper- 
_matozoa themselves are very minute, from s9$95 to sso00 inch in 
diameter. They are active in their movements, the tail was indis- 
tinctly seen, but is present. It is doubtful in my mind whether a 
male eel when less than eighteen or twenty inches long, i. e., when 
in its first year, is capable of fertilizing the eggs, as most of the - 
spermatozoa noticed seemed not fully developed. In males twelve 
to fifteen inches long, č. e., about one year old, the number of 
spermatozoa was much less than in larger, older individuals. 
From information collected from persons living in Providence, _ 
it appears-that the eels begin to descend the rivers and brooks of 
Rhode Island and Connecticut at the first frosts, when fishermen 
begin to catch them in eel-pots. They are in spawn in October, 
November and December, and probably through the winter, and 
they probably spawn in shallow salt and brackish water in har- 
bors and at the mouth of estuaries and rivers, where it is well- 
known eels are speared in winter. That eels spawn in the autumn 
and early winter, and that the young soon hatch, seems proved 
by the fact that young eels from two to three inches long appear- as 
