THE SENSES OF INSECTS. 243 



these should em])race such forms which have apparently a con- 

 genital origin, such as those which reappear from time to time 

 without any assignable environmental interference. The black 

 variety of AmpJtidasis hctularia may be instanced, which crops 

 up sporadically in many districts without founding a permanent 

 colony. In other localities, however, it has become a local race, 

 and requires to be suitably designated. Many other varieties 

 also appear to be entirely referable to ancestral tendencies, 

 occurring in wholly divergent climates, and in regions widely 

 differing in geological and meteorological conditions. Such, I 

 think, are certain of the varieties of Aporoplnjhi, latnleiita. It 

 would be equally necessary to designate sexual and seasonal 

 dimorphic varieties, mountain forms, and those which depend on 

 a high or low range of temperature, or mimicry. The late Mr. 

 Jenner Weir suggested certain terms for some of these ; and 

 "oromorphic" and " pediomorphic " have been used for mountain 

 and lowland varieties ; but until zoological authors generally 

 come to some common decision on the subject, any writer of less 

 degree who avoids a periphrasis by the use of unusual terminology, 

 runs the risk of the stigma of pedantry. 



Drumreaske, August, 1895. 



THE SENSES OF INSECTS. 

 By J. Arkle. 



In the 'Entomologist' {ante, p. 30) Mr. Watson contributes, 

 an interesting article on these speculative topics from the stand- 

 point of the scientist, while I, in a previous number (Entom. 336) 

 record some observations which may occur to the lay mind. 



The error of supposing the existence of an additional sense in 

 insects appears to have partly arisen from a misconception of 

 the power of smell. But, asks Mr. Watson, "What about the 

 antennae?" There is, indeed, much to be said about the an- 

 tennae, for "authorities" have loaded them with almost every 

 sense, including this popular superstition. But why the special 

 development in those of the male ? Simply, I reply, because, at 

 any rate in Lepidoptera, the male seeks the female, as is proved 

 by the habit of assembling. Therefore the male requires, ac- 

 cording to circumstances affecting species, special developments 

 in these antennae or feelers. 



Whether the pituitary body in vertebrate embryos, or, indeed, 

 that anomalous organ in the adult human brain, be a sense 

 structure, a glandular body, or partly sensuous and partly 

 glandular, are matters which still exercise the physiologist. 

 Puzzles they still remain when we exclude such words as 



