Entomology. 177 
The complete account of J. Nusbaum’s investigations on the 
embryology of the opossum shrimp (Mysis) may be found in 
Lacaze Duthier’s Archiv. Zool. Expérim. et Générale, vol. v. An 
abstract of his preliminary note was given in our pages last year 
(Am. Nat. xxi. p. 
ENTOMOLOGY.! 
THE CAUSE OF THE GROWTH OF GaLis.—Herr M. W. Bey- 
erinck has published a paper regarding the growth of the gall 
produced by a saw-fly, Nematus capree, on Salix amygdalina. 
This article appears to be an important supplement to the observa- 
tions of Adler, published some years ago. I have not seen the 
sewn paper by Beyerinck, and therefore quote from an abstract 
of it. 
“ The production of the gall is undoubtedly due to the matter se- 
creted by the poison-gland, which is, consequently, homologous with 
the poison of Hymenoptera aculeata; when the insect does not 
deposit an egg in the wound which it makes, the quantity of albu- 
minous matter poured out by the vesicle is always less than when 
an egg is deposited ; by careful observation it is possible to assure 
oneself that the size of the gall is always proportional to the size of 
the wound and the quantity of albuminoid matter introduced. By 
an experiment, in which the deposited egg was punctured by a fine 
needle, it was shown that the gall is due to the parent and not to 
the egg; but, of course, in such a case’ the gall remains small; 
neither the egg nor the larva are necessary for its production, though 
their presence exercises a certain influence on the regularity of the . 
development. ” 
“ The author has endeavored to discover whether there is any 
persistent alteration in the protoplasm of the plant or not. If we 
Suppose that the substance implicated in the substance of the gall is 
like the protoplasm of the plant, a living body able to grow indefin- 
itely, or a substance which impresses a persistent modification on the 
protoplasm of the plant, we ought, if we should succeed in pushing 
the development of the gall as one of its parts beyond the stage at 
which it ordinarily stops, to find that the characters of the gall 
remain invariably the same. If, on the other hand, the gall-form- 
ing matter can not either grow itself nor form a new protoplasm 
capable of reproduction, we ought, under similar circumstances, to 
find the characters of the organ, whence the gall was developed, 
- 1 This department is edited by Prof. J. H. Comstock, Cornell Univer- 
sity, Ithaca, N. Y., to whom communications, books for notice, etc., 
should be sent. 
les Néerland. Sei. Exact. et Nat., XXI. (1887), pp. 475-92. 
our. Roy. Mier. Soc., 1887, p- 746 7 
