1886. ] Zoology. 71 
THE Division OF THE SEXES OF HyMENOPTERA.—We translate 
in a rather clumsy way Fabre’s interesting article on this subject, 
published in the Annales des Sciences Naturelles (Tome xvii, Nos. 
5 and 6). The entire article should be read to understand the 
subject. 
The Osmias, the Chalicodomas and, as the closest analogies 
show, a great number of other honey-making Hymenoptera, 
arrange their egg-laying in female at first and then in male cells, 
when the two sexes have a different size and require unequal 
quantities of nourishment. If there is an equality of size between 
the two sexes, the same succession may exist, but less constantly, 
This binary arrangement disappears when the place chosen for 
the nest is not large enough for the entire egg-laying. Then par- 
tial egg-layings occur, composed both of females and of males, 
and in harmony, as to their number and distribution, with the dis- 
engaged space. 
To be able to give to each larva the room and the nourishment 
which it needs according to whether it is male or female, the 
mother decides the sex of the egg she is about to lay. Accord- 
ing to the conditions of the home, often the work of another or a 
natural habitation slightly or not at all modifiable, she lays at her 
will either a male or a female egg. The division of the sexes is 
Subject to her will. 
he same prerogative belongs to the carnivorous Hymenoptera, 
the sexes of which have a different shape, and therefore need one 
- More, the other less food. The mother must know the sex of the 
egg she is about to lay; she must dispose of the sex of this egg 
so that each larva shall obtain the right amount of food. 
_ Ina general way, when the sexes are of different size, every 
insect which collects the living prey, which prepares or at least 
chooses an abode for its offspring, must decide the sex of the egg 
to satisfy without error the conditions imposed upon it. 
It remains to tell how this elective determination of the sexes is 
made. I do not absolutely know, I have never understood this 
delicate problem but attribute it to some fortunate circumstance 
which it is necessary to know or rather to watch for. 
EnTomotocicaL News.—From a series of experiments by Pro- 
fessor Graber, says Nature, Oct. 22, relating to the effects of odor- 
ous matters on invertebrate animals, it appears probable that in 
the case of many insects neither the antennz nor the palpi can 
be absolutely pronounced the most sensitive organ of smell, 
inasmuch as the one organ is most sensitive to some odorous 
matters, and the other for others. —- Apropos of Hickson’s 
account of the structure of the eyes of insects in our last number, 
we may say that, in 1883, B. T. Lowne published a paper in the — 
Proc. Roy. Soc. London, of which an abstract has been published 
by Dr. Mack in Psyche, as follows: The author claims four forms fe 
