ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 
53 
bacli’s) researches on the spermatozoa of Dytiscus marginalis. It is the 
old tiresome question of priority. More interesting is the reference to 
Selenka’s description of double spermatozoa in DidelpJiys, which seems 
rather the results of incomplete separation than of conjugation of 
spermatozoa. 
Copulatory Organs of Male Hymenoptera.* — Herr C. Verhoeff 
asks whether the Hymenoptera possess the homologues of the “ laminae 
basales ” of male Coleoptera. These latter are parts which the author 
regards as of great phylogenetic significance. He concludes that though 
the parameres of the Coleoptera and Hymenoptera are homologous there 
are no homologous basal plates in the latter. 
They have, however, an organ which is physiologically very like the 
basal plates, and he proposes to call it the lamina annularis or circular 
piece ; he regards it as of great value in determining natural affinities. 
The organ in question was discovered by Hoffer and Schmiedeknecht, 
both of whom gave it the inappropriate names of cardo or capsule. 
Male Genital Apparatus of Hymenoptera.f — M. Bordas, who has 
examined these organs in Apis mellifica, finds reason to differ from many 
of the results of his chief predecessors. He gives, however, only an 
account of his own observations, which appear to be limited to points of 
detail. There are some notes also on the same parts in Vespa rufa ; 
other species have also been studied, and there appear to be considerable 
differences among them. 
Copulatory Organs of Libellulidse.t — Herr J. Ingenitzky gives an 
account of the male generative apparatus of JEschna grandis and 
JE. cyanea. It consists of six pairs of unjointed chitinous plates, at- 
tached to the second abdominal segment and very probably serving as 
an apparatus for seizing the female copulatory organs, and of a three- 
jointed penis which arises from a bulb which is attached to the third 
ventral segment. 
This bulb contains a seminal reservoir in which the tubes of sperma- 
tozoa lie before copulation ; the reservoir is completely separated from 
the coelom, and passes into the canal of the penis ; the walls of it and 
of the canal consist of a layer of small cubical cells, which secrete a thin 
chitinous cuticle. The cavity of the reservoir varies considerably in 
size at different times, being, when empty, compressed by the elastic 
sacs which surround it on either side. The walls of these sacs consist 
of a high epithelial layer, which passes directly into the hypodermis of 
the bulb ; in the interior of the sac there are branched chitinous fila- 
ments which are connected with the chitinous wall of the bulb. The 
sacs are closed invaginations of the hypodermis. into which neither nerves 
nor tracheae enter ; their function appears to be to cover and protect the 
seminal reservoir. The musculature of the bulb, notwithstanding the 
statements of Rathke and Burmeister, is very feebly developed. 
The bulb is richly supplied with tracheae, which are wanting, how- 
ever, within the seminal reservoir ; they are accompanied by nerves from 
the third ventral ganglion. 
* Zool. Anzeig., xvi. (1893) pp. 407-12 (6 figs.). 
t Comptes Rendus, cxvii. (1893) pp. 746-8. 
X Zool. Anzeig., xvi. (1893) pp. 405-7 (2 figs.). 
