LEPJDOPTERA. 
443 
An elaborate anatomy of tlie eyes of caterpillars, with a com- 
parison of their structure with that of the facetted eyes of perfect 
insects, from which it appears that these organs are nearly iden- 
tical in their essential construction. 
Pasteur, — . Nouvelles etudes experimentales sur la maladie 
des vers h soie. Comptes Bendus, Ixiii. pp. 897-903 : No- 
vember 1866. 
. Observations au sujet d^uneNote deM. Balbiani relative 
h la maladie des vers h soie. Ibid. pp. 441-443 : September 
1866. Observations relatives h cette communication [de M. 
Bechamp]. Ibid. pp. 427-428. 
General Notes. 
Gabriel Koch (Die Indo-Australische Lepidopteren-Fauna) 
has subjected the geographical distribution of this order of in- 
sects to an elaborate discussion. lie maintains that, as regards 
the Lcpidoptera, we may divide the earth^s surface into three 
great regions : — the American, including the whole of the western 
continent south of 60° N. lat. ; the European, including the 
whole continent of Europe, with the Mediterranean district, the 
northern and temperate parts of Asia, and apparently the whole 
continent of Africa, although this has Indian affinities ; and the 
South Asiatic or Indian, of which the Australian and Polynesian 
regions are to be regarded as continuations. In support of these 
views, he dwells, in the first section of his Division I., upon the 
general laws of the specific diffusion of insects, especially Lepi- 
doptera, in which he admits the coexistence of two momenta — 
namely, the simultaneous production of identical species in dif- 
ferent places (which is adopted mainly to account for the occur- 
rence of species having wingless females, P sy chides, \i\ widely 
separated localities), and the gradual dispersion of species by the 
exercise of their powers of flight aided by atmospheric currents. 
In connexion with the latter proposition, he discusses at consi- 
derable length the phenomena of the monsoons in the eastern 
seas, and argues from them in favour of the possibility of the 
conveyance of insects possessing considerable power of flight, like 
the Lcpidoptera, through the chain of islands forming the 
Eastern archipelago, to the Australian and Polynesian regions. 
In a second section of the same division Koch discusses the 
production of colours in the pupae, and the formation of varieties.^^ 
He maintains that, although light may have some influence on 
the production of colour in insects, there are many cases in 
which brightly coloured species pass their pupa-stage either con- 
cealed in the burrows formed by their wood-eating larvae, or 
buried to a considerable depth in the ground, and therefore 
sheltered from the direct influence of light ; and suggests that 
the effect of light may be indirect, by its affecting the plants on 
