1880. | Zoology. 601 
that the study of the histological structure of the organs of 
Syrski can bring us somewhat nearer to the truth of the matter.” 
He then describes the lobulated organ of Syrski, found also in 
American males by Packard and Kingsley. Cattie also describes 
what he regards as the seminal duct, previously studied histologi- 
cally and so considered by Freud.) Its structure is like that of the 
immature teStes of fishes. In the largest of the eel with the or- 
gans of Syrski (lappenorgan), which was 445 centimeters in length, 
Cattie found a tube-like cord, which extends from the base to the 
end of the bow-shaped indentation of the streak which extends 
along the testes, and which is filled with cells. This string of 
cells shows the most undoubted similarity to the sperm mother- 
cells of the testes. He observed no spermatozoa in his eels. 
Cattie then quotes the sexual differences in the eel given by 
Jacoby.? These are differences in the head; which is broader in 
the females, than the narrower and more pointed snout of the eels 
with the lobulated organs of Syrski; all the females moreover have 
a higher, broader dorsal fin than the males, while the latter are 
said to be darker green, more metallic on the sides, and blacker 
on the back of the body; and eels with the organs of Syrski 
have larger eyes, though Jacoby states that large-eyed females 
also occur. Cattie’s measurements confirm Jacoby’s statement that 
the females have a higher dorsal fin; he thinks that the females 
on the whole have larger eyes, while the best external sexual dif- 
ference is the smaller and more pointed, less flattened, more con- 
vex head of the males; but he found no permanent differences of 
coloration. 
as these bodies before the matter can be regarded as finally 
Send. ™ >, 
NOTES ON THE WINTERING OF THE Ropin.—I see that in the last 
NATURALIST, the appearance of robins at Evanston, Ill., is made 
the text for a theory of bird migrations. In Western Iowa, at 
about the same latitude, robins remain in wooded valleys through- 
out the winter. Last December I observed them in flocks in the 
underbrush along the Missouri river, opposite Plattsmouth, Neb. 
n the uplands, which are about three hundred feet higher and 
* Litzungsberichte der Kais. Akad. der Wissenschaften. Wien, 1877, Marzheft. 
* Dr. L, Jacoby, Der Fischfang in der Lagune ven Commachio. 
VOL, X1v.—No, VHI. 39 
