712 
Analyses of Books, 
[November, 
Mr. Swinton enters at considerable length into the question of 
the funftion of the antennae in inseas. He does not, however, 
refer to certain experiments which to us appear crucial. Insects 
when their antennae were coated over with wax or varnish have 
been found utterly unaffeaed by fumes from which under all 
other circumstances they shrank back. , „ 
Many interesting cases are given of the recognition of colon 
by inseas, and we find here a suggestive remark that the gradual 
extinaion of species attendant upon the clearing of foiests, 
drainage of swamps, and cultivation of heaths may be in some 
measure due to the removal of mimetic shelter. Mr. Swinton 
considers that browns, blacks, chl ° ro P h >' 11 / mt ^^ a ^ i P“ r t P ug Ws 
the pigments we notice on protected surfaces, whilst the hues 
specially designed to evoke the passions consists mainly in 
white and its prismatic elements. We have long considered 
bright and pure hues* as connected with the highest vital y. 
The author considers that the hind wings of a beetle are m™ - 
sally colourless. This is not absolutely correa. The posterior 
win^s e.g., of the Colorado beetle are pink ; those of Lomaptera 
VrvMei a beautiful violet blue ; of Behonota fallacies a 
deep brown, of Cotinis mutabilis a greenish bronze on the ant ®P°r 
margin and of a blue shade on the posterior, the intermediate 
portfon being of a reddish bronze. We have indeed noticed so 
many changes of decided colour in this part that we think the 
wings of every new or imperfealy known species should be care- 
fully examined on capture. . . , 
Mr. Swinton raises further the very interesting question how 
the pattern is produced upon the wings of inseas, especially 
butterflies. Does the secreted colouring matter “ flow from the 
thorax through the tissues of the flaccid wings, and are the stains^ 
impressed by their membranous coverings in the mannei of a 
printing press ? In support of the latter hypothesis he mentions 
that a specimen of Leucania conigera captured near the Welsh 
Haro Tavern to the north of London in 1877 was found to have 
”e marirings upon the upper wings reproduced on the upper 
surface of the left lower ; and a specimen of the common Meadow 
Brown taken near Oxford in 1878 showed the same transforma- 
tion effeaed in the under surface of the same wings, accompanied 
whh the development of an additional vein and consequent 
enlargement that seemed to afford a reason how the hind wing 
came^to be folded so as to receive not alone the impress of the 
inferior side but the very eye-spot of the upper. 
Neither of these hypotheses, however, is quite free from diffi- 
culties We find in some cases, e.g., Apostrophm charitoma 
Papilio Podalirius, and many more which t n V g nl, b ® nd 
selected the under surface merely a somewhat dulled and su 
dued reproduaion of the upper. In such a case we might readily 
* Journal of Science, 1878, p. 37* 
