781 
1880.] Analyses of Boohs. 
shaped, whilst the eggs of V. Io and V. Atalanta are ribbed and 
cylindrical, — a phenomenon which deserves more extended in- 
vestigation. 
He considers that the difference of sex is to be traced even in 
the egg, and is not, as some naturalists assume, influenced by 
the larger or smaller supply of nourishment during the larval 
condition. In connection with this subjeCt he enters upon the 
question of parthenogenesis, — a phenomenon far from rare among 
certain Micro-Lepidopterous genera; e.g., Fumea and Solenobia. 
He finds it thoroughly established that the females of species 
belonging to these groups, without impregnation, deposit eggs 
from which larvae are produced. Such caterpillars yield, how- 
ever, female moths only, which continue to reproduce themselves 
in the same manner. Whether this kind of propagation is limited 
to a certain number of generations or may go on indefinitely 
does not appear. 
Turning to the larvae of moths and butterflies, Herr Keterstein 
devotes much attention to the irritant and poisonous secretions 
of many species. In certain species the hairs appear to be 
hollow, forming veritable stings, and are connefted with true 
poison-glands at their base. Naked caterpillars are also poisonous. 
Prof. Zeller suffered severely from touching the larvae of Depres- 
saria venificella, which he found feeding upon Thapsia gargarica , 
in the neighbourhood of Syracuse. 
On the diet of Lepidopterous larvae we find a great number ot 
observations, far more species being carnivorous than it is com- 
monly supposed. 
It is remarkable that whilst the caterpillars of some butterflies 
can be reared up to maturity in utter darkness, those of Parnas - 
sins Apollo , according to Prof. Von Siebold, refuse to feed in 
the dark. . . . . 7 
It is well known that the adult death’s-head moth (. Acheronha 
Atropos) utters a squeaking sound if touched, but, according to 
Brauer, its larva stridulates alsn. . 
That the caterpillas of certain species should in their earlier 
stages appear respectively undistinguishable, and should after- 
wards assume characteristic differences, is what we should expeCt 
according to the principle of Evolution. But the larvae of Danais 
Phidippus and Bombyx Vishnu , two species remote from each 
other in any possible classification, can only be distinguished by 
their respective size and by the plants they feed upon. On the 
other hand, there are cases (A crony eta P si and tridens) where 
the perfeCt inseCts are scarcely to be distinguished, whilst their 
respective larvae are plainly different— a most perplexing fadl, of 
which several instances are known. 
As regards the pupa-state there are, as might be expected, 
fewer interesting phenomena to put on record. Pupae aie, how- 
ever, by no means so helpless, motionless, and unconscious as 
they are often represented, and the notion — common among the 
