30 Recent Literature. [ January, 
ley, who adopted the view that the bodies he saw could not have: 
been anything else than spermatozoa. My friend, Prof. John Pierce, 
an experienced microscopist, several times with me examined 
the free moving spermatozoa (we saw hundreds in active motion), 
and agrees with me that the bodies we repeatedly observed from 
different males could not have been organic particles vibrating 
through the Brownian motion. We both, without distinctly 
observing the tails, witnessed effects that must have resulted from 
a rapidly vibrating appendage or “ tail.” 
NoTe.—Since the above was written I have received (Dec. 12) from Mr. Vinal 
N. Edwards, of the U. S. Fish Commission, a ie of eels from’ Wood’s Holl, 
Mass., forwarded at the suggestion of Prof. Baird. Ther two races or varie- 
ties among them, some dark with yellow on at tally, aie yee and silvery be- 
neath, with the anal fin bright red, as well as the edges of the pectoral fins, I sup- 
posed that the yellow bellied ones were females and the silver rages ones were 
males, but found males and females of both races; so that while the above remarks 
concerning the colors of the sexes may apply to what eels I e from Provi- 
ence River, in the Wood’s Holl specimens, there was absolutely no coloration 
difference between the sexes, and the difference in color is probably due to the color 
of the water, and especially the nature of the sea bottom, whether sandy or muddy. 
The females from Wood’s Holl were about ready to spawn, and the males contained 
more abundant spermatozoa than any others examined, but no milt. 
:0: 
RECENT LITERATURE. 
Sars’ Motiuscan Fauna oF Arctic Norway.!—The connection 
between the northern faunz of East America and Europe is so 
close that monographic work of any kind done for one region, 
deserves and usually obtains the careful attention of students 
whose field of research is in the other; and it is daily becoming — 
more necessary as wider observation reveals with greater clear- — 
ness the intimate relations which the two districts bear to one 
ability of the author as an observer, an investigator and an artis- 
tic delineator of the objects he describes, warrant us in expecting 
results, in the main, of the highest excellence. Yet candor com- 
pels us to admit that these expectations are only partly fulfilled. 
The work contains a short introduction followed by a descrip- 
_ tion of each species in zoological order, without synonymy or des- 
aeria til PRENS om Norges — Fauna, 1, Mollusca Regionis Arctic 
No Af Dr. G. O. 
2 Sars, Prof. Zoöl. v. Christiania Univ. Universitets pro- 
-gram for Lori halvaar 1878. “Christiania, 1878. - 8vo, pp. 456. a and fift yur © 
autos sraphic pla 
