1222 Generar Notes. | December, 
the abdomen of a crab, is in reality the abdomen of an arachnid, 
of which six species are now known, one from the coal measures 
of Arkansas. In A. Walter’s article on the morphology of 
Lepidoptera in the Jenaische Zeitschrit for May, we have an ac- 
count of the mouth-parts of Acentropus. The transformations 
of Paraponyx oryzals, an insect pest of the rice- plant in Burma, 
are described and well figured by J. Wood-Mason, in a pamphlet 
printed in Calcutta. Its larva is aquatic and breathes by tracheal 
gills. We wish the author had given more detailed sketches of 
the gills and their relation to the body. We omitted to note 
Kowalevsky’s contribution to the post-embryonal development of 
the Muscide in the Zoologischer Anzeiger for Feb. 23, 1885. 
ZOOLOGY. 
THE SIGNIFICANCE OF THE CELL NUCLEUS TO THE PROBLEM OF 
HeErepi1y.—The results of the later researches upon fertilization 
and cell division, have tended to make biologists view the cell 
nucleus as of pre-eminent inportance for the life of the cell. In 
1884, Kolliker, in his Entwickelungsgeschichte, stated, that 
since fertilization consists essentially in the fusion of a male with 
a female pronucleus into one segmentation nucleus which entails 
its hermaphrodite character upon its offspring of cell generations 
during ontogenetic development, this fact gives us the true reason 
why, and how every organism resembles its parents. The last 
two years have been fruitful in discussions of the problem of 
heredity in the light of nuclear investigations and have stimulated 
Kolliker to expand the above statement with more completeness 
and detail in the paper? of which this article is an abstract. 
From our present knowledge of the biology of the cell nucleus 
we may draw certain conclusions of great value as a basis for the 
discussion of the problem of heredity, as follows : 
The nucleus, and it alone, contains a substance which possesses the 
power of building up an organism according to specific characters, 
making it resemble the parents from whieh the nucleus origi- 
nally came—in other words, possesses the hereditary power. 
This follows from: 
(a) The nature of the spermatozoin: 
We know that but one spermatozoon is needed in the fertiliza- 
tion of one egg; we know that this must carry the hereditary 
traits of the father which he received from his ancestors both male 
and female; each spermatozoon is a nucleus. 
Kölliker, in 1844, held the spermatozo6n to be the equivalent 
of a cell, but later came to the conclusion that it represents a nu- 
cleus., Other Other biologists agreed with Kölliker so far as the dody 
of the Fptrmatosoòn is concerned ; but the fagellum, they said 
ts the cell protoplasm ; and hence a spermatozoon may 
ig der Zellenkerne fiir die Vorgänge der EAR r? Zeitschrift 
Zoologie. eee RAH, erstes erstes hqft. July, 183. 
