xly 
birds to the Heliconiide, which were referred to on the former occasion, and in 
| Mr. Bates’ paper in the Linnean Transactions. 
Mr. T. Belt gave a detailed narration of bis observations on this subject, and stated 
| that not only were the perfect insects of Heliconia protected by their unpleasant odour, 
| but that the larve also were rejected by fowls. 
Mr. Stainton remarked that a curious instance of the dislike which birds seemed to 
| have for certain insects had come under his observation some eighteen years previously. 
| When he was attracting moths by light, he had often such numerous attendances that 
| he had frequently captured fifty Noctue, or more, in a quarter of an hour; whatever 
| came must be caught, or it was in the way, and, in order to ascertain most readily 
| whether there was anything of value, Mr. Stainton adopted the plan of smothering the 
| whole lot with the fumes of sulphur. When the operation had been performed, more 
| than nine-tenths of the dead insects would probably be Agrotis exclamationis. He 
| thus had a vast store of useless dead moths, which he disposed of by giving them to 
the poultry, the young turkeys particularly enjoying them in spite of their flavour of 
sulphur. On one occasion, amongst a number of A. exclamationis, there was one 
specimen of Spilosoma Menthastri, and though not one of the young turkeys rejected 
a single A. exclamationis, they each in succession took up the 8. Menthastri and put 
it down again, and it was left, conspicuous as it was, on the ground. This insect, it 
was well known, had a peculiarly disagreeable odour. 
Mr. J.J. Weir had frequently noticed that cage-birds refused the jane both of 
Spilosoma Menthastri and S. lubricipeda. 
Prof. Westwood stated that a fluid of very disagreeable odour was emitted by those 
insects from behind the collar; this was probably similar to that ejected by many of 
the Chrysomelide. He inquired whether anything of the kind had been observed in 
the Heliconiide. 
Mr. Bates said that one group of Heliconiide was furnished at the apex of the 
abdomen with a process from which, when the abdomen was pressed, a very disagree- 
able odour was exhaled ; but he had never seen any fluid ejected. 
Mr. McLachlan remarked, as bearing upon the theory of Natural Selection, that 
having recently been engaged in an examination of the British Psocida, in which 
family the generic or sectional characters were principally grounded on the neuration, 
he had found occasional instances of aberration in the arrangement of the veins: 
these aberrations consisted in one wing of an insect which belonged to a particular 
genus or section assuming, entirely or partially, the neural characters of another genus 
or section ; in no case, among several hundred examples, did he find neural variation 
which was strictly abnormal. 
Dr. Sharp offered some criticisms on the theory advanced by Messrs. Bates and 
Wallace, and argued — 
Ist. That natural selection was a power of differentiation, and, although it was quite 
possible that a differentiating power might work so as to produce resemblances, it was 
at first sight improbable that it should do so; and more evidence was required of the 
truth of a paradox than of a truism. 
2nd. It must be shown that animals possessing the so-called mimetic resemblances 
occurred far more frequently in company with one another than away from one another. 
But if this were shown, a single case of such resemblance between animals living in 
different localities would throw doubt on the theory, by suggesting that there was 
