276 QUARTERLY CHRONICLE. 
in order to judge of this value, three preliminary questions 
must be answered : 
1. Whether the structure of the shell in the same egg is 
uniform throughout. 
2. Whether the histological composition of the shell is 
eonstant in one and the same species. And 
3. Whether constant differences can be discerned between 
nearly allied species. 
The general conclusions at which he arrives, after extended 
researches, which are admirably detailed in the paper before 
us, seem to be that the intimate structure of the egg-shell 
possesses scarcely any greater systematic value than do the 
external macroscopic characters; and consequently, that 
oology, even with this addition, stands just where it did, as 
regards systematic ornithology. 
8. “ Observations on a former Communication by Landois,”’ 
(Zeitsch. f. w. Zool. Bd. xvi, pp. 375), by Professor V. 
Siebold.—These observations, by Professor V. Siebold, have 
reference to M. Landois’ assertion that in the eggs of insects 
—or, rather, it should be said, in the embryo—of insects, 
while still within the egg, there are no distinct indications of 
the future sex, which, according to him, is determined after 
the escape of the embryo from the egg, by differences in the 
food with which it is nourished. ‘This extraordinary statement 
is apparently supported by experiments which M. Landois 
made with bees, and consisting in the removal of the egg which 
had been laid in a ‘‘ drone-cell”’ into the cell of a ‘* worker,” 
and vice versd, in consequence of which he states that the sexes 
were developed also, apparently in accordance with the 
change of locality, and, as he supposes, of food; being ap- 
parently ignorant of the fact that up to the sixth day, at 
least, of the life of the maggot, before which time the sexual 
organisation is manifest, both workers and drones are fed 
upon the same food. Professor V. Siebold expresses con- 
siderable doubts as to the correctness of the results arrived at 
in these experiments, and adduces numerous instances in 
other insects which tend to show that M. Landois’ hypothesis 
strongly requires further evidence in support of it before so 
strange an anomaly can be admitted into science. 
And in this view, V. Siebold is briefly followed in the next 
article. 
9. “On the Law of Development of the Sexes in Insects,” 
by Dr. Kleine, whose observations, however, are limited to 
the question of sex in bees only; with regard to which 
insects he considers that M. Landois is but imperfectly im- 
formed, whatever value may attach to his observations in 
other parts of Entomology. 
