(Eb) 
production of seasonal dimorphism in many parts of the 
tropics, as that of hot and cold ones is in the temperate 
latitudes. 
I must confess that I shared in the prevalent erroneous 
opinion that seasonal dimorphism was not to be looked for in 
countries without summer and winter seasons of greatly 
differing temperatures; and no doubt this was mainly due to 
my never having resided for any length of time in a region 
where the rainy season is the warmer and the dry one the 
cooler. In the south-west of the Cape Colony, where I was 
stationed, exactly opposite conditions prevail, and in the 
rainy winter, scarcely a dozen species of butterflies appear, 
and none of them presents any marked difference from the 
dry summer specimens of the same species. I was thus 
unprepared to attach due value to the suggestion, by my 
friend, Mr. W. D. Gooch, as early as the year 1877, of the 
occurrence of differing seasonal forms of butterflies in Natal, 
or to the opinion to the same effect given by Mr. A. J. Spiller 
in 1880 (‘‘ Entomologist,” vol. xiii, p. 3). I believe this 
communication of Mr. Spiller’s to have been the first 
published intimation of the apparent occurrence of seasonal 
dimorphism in the warmer parts of the world ; and the four 
cases which he specially notices (in the genera Anthocharis 
[= Teracolus], Pieris, Mycalesis, and Hypanis) are un- 
doubtedly true ones. Mr. Gooch (op. cit., pp. 226 and 273) 
published his concurrence in the main with Mr. Spiller’s view, 
but at the same time mentioned that, in the only two attempts 
he made to test the matter, by rearing Zeracolus omphale and 
Pieris severina, he found no difference between the winter and 
summer broods, both belonging to the theoretical winter form 
with reduced black markings. 
It was in 1885 that Mr. L. de Nicéville, the well-known 
authority on Indian butterflies; published* a notice of 
apparent seasonal dimorphism in several species of Calcutta 
Satyrine of the genera Mycalesis, Ypthima and Melanitis—the 
wet-season form presenting distinct ocellated spots on the 
* <¢ List of the Butterflies of Calcutta, etc.” (Journ. Asiat. Soc. Bengal, 
liv, plssaisps189.) 
