42 A NATURALIST IN THE TRANSVAAL. 



unison ; but though I watched for months to see a 

 specimen thus situated, and with its wings vertically 

 closed, I never succeeded in doing so. 



Thus, if the reports as to its habits in Seuegambia, 

 Calabar, and Cameroons are correct, we have not only 

 a change of habit with difference of latitude, but also 

 what I have elsewhere ventured to describe as an 

 instance of " Compound Protective Resemblance " *. 

 For we see that while in Senegambia, Calabar, and 

 Cameroons, where (according to report) the butterfly 

 always settles with wings vertically closed, and which 

 " so closely resemble the soil of the district, that it can 

 with difficulty be seen, and the colour varies with the 

 soil in different localities," in the Transvaal and Natal 

 it rests with horizontally-expanded wings f , by which its 

 protection is almost equally insured by the assimilative 

 colour of the same to the rocks and paths on which 

 it is usually found. My friend Mr. Trimen, with 

 whom I discussed this matter, suggested that I should 

 observe whether the upperside might be protective in 

 the wet season, and the underside in the dry ; but what- 

 ever may be the case elsewhere, I saw that its habits 

 W 7 ere uniform in the Transvaal in both the diy and wet 

 seasons. 



I was afforded a good opportunity of watching the 

 gradual approach of spring and summer, with their 

 transforming effects in the production of plant and 

 insect life, as business weekly compelled me to drive 

 some 15 miles out from Pretoria to a Boer farm, on 

 the hills of which grew a tree capable of supplying bark 

 for tanning-purposes. This was called the " sugar-tree ;" 

 but the bark Avas coarse and possessed little strength. 

 The best and strongest tanning-material in the Transvaal 

 appears to be the leaf of a tree (CoJpoon compression}^ 



* ' Nature,' vol. xlii. p. 390. 



f Although as a general rule the species of Nymphalidse, to which family 

 this butterfly belongs, do rest with vertically closed wings, the species of the 

 tropical American genus Ageronia have a similar habit to //. (hcdahis as 

 observed iu the Transvaal. 



J For the exact identification of this species, I am indebted to the Curator 

 of the Durban Botanic Gardens, 



