Rhopalocerous forms in South Africa. 273 



of apparently important differences. The multiplication 

 of species and their barbarous names involves a considerable 

 waste of valuable time, and implies in some cases labour 

 lost in an ignis fatuus search for innumerable synonyms. 



In some resj)ects it retards biological progress, for many 

 persons who would gladly follow natural history pursuits, 

 are deterred by the foi-midable bibliographical folios, Avhich 

 it is too often necessary to consult. 



The next specimens exhibited afford an illustration of 

 some of these remarks. 



In the " Saturday Review" for 16th June, 1877, I find 

 the following remarks in reference to Mr. Darwin's last 

 work : " No absolute definition of species has ever been 

 found possible. What is called fixity of species is the 

 result of the continuity of external conditions. So long 

 as the biological conditions remain unchanged, there is no 

 reason Avhy a species should vary." 



Yet in the face of these remarks I now present to the 

 Society one of the most curious cases of variation I have 

 yet met with. 



In Ml-. Trimen's Ehop. Afr. Aust., Vol. I., is described 

 Anthocharis ( Callosune) Keiskamma, Trim., a species 

 there noticed as not improbably capable of being classed 

 as a sub-species of C. Evarne. Both of these butterflies 

 I have often seen in the neighbourhood of the Keiskamma 

 River, the former being especially abundant, in fact, the 

 whole valley of the Keiskamma is peculiarly prolific in 

 Callosunes. During the last three years I have been 

 staying about three miles fi-om King Williamstown in the 

 valley of the Yellowwoods, and I was much struck by the 

 abundance of C. Keiskamma near a small group of bushes 

 jfrom January to May, 1876, especially so, as I had not 

 met Avith the insect in the neighbourhood before. The 

 spot in question is about fifteen miles in a direct line from 

 the Keiskamma with high ground intervening. I cap- 

 tured that season about twenty or thirty of both sexes, 

 and wishing to discover the food ]j]ant I noticed that the 

 butterflies especially frequented a bush, which I had not 

 before noticed. This proved to be Cadaha Natalensis 

 ( Capparide(B), not hitherto, I believe, reported fi-om the 

 South of Natal. The $s deposited their small, fluted, 

 orange-coloured eggs singly on the summit of the flo^vcr 

 buds. A chrysalis was also foimd on one of tlie outer 

 branches of a bright-green colour, and it proved to be that 



TRANS. ENT. SOC. 1877. rART III. (OCT.) U 



