1866. | ( 581 ) 
V. ENTOMOLOGY. 
(Including the Proceedings of the Entomological Society.) 
Tue old opinion as to the hermaphroditism of the viviparous 
Aphides has been revived by M. Balbiani. According to his state- 
ment in the ‘Comptes Rendus,’ the main facts seem to be that 
the vitelline vesicle separates into two cells, and that each of these 
cells subsequently becomes covered on its surface by a generation 
of small cells which gradually increase in size and number. From 
these two cellular groups, placed side by side in the cavity of the 
blastoderm, originate the male and female elements of the future 
animal—that is to say, of the ova in the one and the spermatic 
fecundating corpuscules in the other. The formation of the 
spermatic bodies commences very early, for all the embryos of the 
viviparous aphides at the moment of their birth contain new 
generations in the course of development. The observations which 
M. Balbiani has made indicate, he thinks, that the egg, while in 
the ovary, undergoes a first fecundation with which the male has 
nothing to do, and the effect of which is limited to the generation 
of the elements of the future animal. In the oviparous aphides 
the formation of the embryo does not commence until after the 
fecundation by the male and the deposition of the egg which 
succeeds, 
In the ‘ Annales de Sciences Naturelles, Zoologie’ (July, 1866), 
M. Memert calls attention to two articles published by him in the 
‘Naturhistorik ‘Tidsskrift,’ the one sustaining the opinion of 
the origin of the Cecidomya larve in the adipose tissue against the 
opinion of M. Pagenstecher (ante, p. 269); and the second 
asserting that the statements of various observers have been 
drawn from two different forms belonging to very different genera 
—the Miastor metraloas (the one on which Professor Wagner’s 
discovery rested), and a hitherto undescribed species which he has 
characterized under the name of Oligarces paradowxus ; in neither 
is there formed an ovary properly so called, as M. Leuckart has 
asserted. The egg he considers to consist of a single cell, “la 
cellule germinative.” 
Dr. Packard has communicated to the ‘Annals and Magazine 
of Natural History’ (August, 1866), a paper recently read before 
the Boston (U.S.) Natural History Society, entitled “ Observations 
on the Development and Position of the Hymenoptera, with Notes 
on the Morphology of Insects.” The “ observations” were chiefly 
made on the genus Bombus, and its successive stages are minutely 
described. The author considers that twenty rings, or somites—for 
which he proposes a new name (arthromere)—as a rule, compose 
the body of insects, of which seven are contained in the head, 
