The Bionomics of South African Insects. 461 



Di:. W. Hatchett Jacksou, the Radcliffe Librarian at 

 Oxford, permits me to publisli the following observation 

 made by him at Weston-super-Mare in the second week 

 of January 1895. Dr. Jackson found, in the garden of 

 his house, on the side of a hill sloping south, about twenty 

 peacock butterHies hybernating in the heart of a bramble- 

 bush. The butterflies were arranged in rows on two or 

 three approximately horizontal runners about a foot from 

 the ground. All rested with their wings hanginfj down- 

 wards. When the butterflies were first disturbed they 

 made no movement, but on repeated disturbance they 



specimens in the hollow formed by the arching roots of a large beech- 

 tree, in Dec. 1852 (G. C. Barrett, British Lepidoptera, London, 

 1893, vol. i, p. 139). W. S. Coleman (British ButterHies, London, 

 1862, p. 88) quotes Doubleday in the Zoologist: — "Last winter some 

 large stacks of beech faggots, which had been loosely stacked up in our 

 forest {Ep'plmj) the preceding spring, with the dead leaves adhering 

 to them, were taken down and carted away, and among these were 

 many scores of io, uytica.', and 'polijcldoros." No reference is given, 

 and I have failed to find the original statement. An observation of 

 Mr. Banning of Monte Video, Ballacraine, Isle of Man (also quoted 

 by Coleman, 1. c. p. 91), is recorded in the Zoologist (1856, p. 5000) : — • 

 " Whilst standing in my farmyard on the day following Christmas 

 Day [1855], it being unusually fine and warm, I was suddenly 

 astonished by the fall of more than a hundred of the accompanying 

 butterflies [Vancasa urticx]. I commenced at once collecting them, 

 and succeeded in securing more than sixty. . . ." This observation 

 apparently points to the emergence of a hybernating assemblage in 

 consequence of exceptionally warm weather. It also indicates con- 

 ditions which at a normal time of the year would be favourable to 

 pairing. 



Mr. J. W. Tutt states that the imagines of V. io feed largely during 

 August, disappearing at the end of the month or in September 

 (Entomologist's Record, 1895-6, vol. vii, p. 3). It is therefore 

 probable that the butterflies produced by one company of larvte do 

 not keep together, or the fact would certainly have been noticed 

 when they are in search of food. It is probable that the products of 

 all companies scatter and become thoroughly intermingled before 

 again assembling into groups for hybernation. Another line of 

 evidence may perhaps yield incontrovertible proof of the existence 

 of this intermixture before reassembling — a probable adaptation to 

 prevent in-and-in breeding. Dr. W. H. Jackson and Mr. 0. H. 

 Latter, F.E.S., have found that the pupa3 obtained from dift'erent 

 batches of larva) of V. io " were principally, but not entirely, of one 

 or of the other sex" (Trans. Linn. Soc, London, vol. v, 1890, p. 156), 

 It would not be ditficult to obtain a numerical statement of the 

 average constitiition of a company in this respect, so that it would 

 be available for comparison with that of a hybernating group. A 

 marked diflerence would prove intermixture before hybernation, 

 while a similar constitution would yield negative evidence. 



