Seasonal Dimorphism in Btotterjlies. 201 



(of which yours is one) are quite similar, but the third has 

 the black edging to the apical patch of the forewing a trifle 

 heavier, and also shows a trace of the black line along the 

 inner edge of the patch characteristic of the full summer 

 form. As the eggs were all laid by the same female, and 

 the larvae were reared under absolutely similar conditions, 

 it would seem at first sight that the heavier markings 

 could only be due to the longer larval stage, but this seems 

 highly improbable. I was astonished at the rapid develop- 

 ment of this species ; egg-stage, three days ; larval stage, 

 twelve to thirteen days ; pupal stage, eight days. Total, 

 twenty-three to twenty-four days. From this I should 

 estimate that there must be from nine to ten broods in 

 the year."— G. A. K. M. 



The above-mentioned specimen, a male, is now in the 

 Hope collection, and entirely bears out Mr. Marshall's 

 description. It is a well-marked, but not extreme example 

 of the " wet-season " form T. auxo, Luc. Mr. J. Mansel 

 Weale's experience of the same species is well known ; * 

 and it may be noted that of five bred examples sent to the 

 Hope collection by Mr. Weale in 1878, there is a pair each 

 of the auxo (wet) and to2}ha (dry) form, together with a 

 single female of an intermediate phase. Mr. Marshall's 

 experiment removes the subject of the specific identity of 

 these several forms from the region of probable conjecture 

 to that of proof. 



" Estcoiirt, Dec. 14, 1896. — While staying with Mr. Burn, 

 at the junction of the Blaauwkraantz River with the Tugela, 

 I tried to see whether the black markings of the early wet 

 brood of Teracolits anUc'B could be intensified by damp 

 surroundings, so as to resemble those of the full wet form. 

 For tliis purpose I had a tin half filled with wet sand, 

 in which I stuck the pupa? on thin sticks, covering it 

 over with a cloth on which was a wet sponge. Into this 

 I put five freshly-turned pupoe, of which I kept three in 

 for seven days and two for nine. Only one specimen 

 emerged out of each lot, and so far as I can see there 

 is absolutely nothing unusual about either of them. 

 Although the results of the experiment are negative, they 

 are interesting, in that they tend to show that cold moisture 

 cannot accentuate the black markings of the wet-season 

 form, and also that cooler surroundings (induced by evapor- 



* Trans. Ent. Soc. Lond., 1877, p. 273. See also Mr. Barker's 

 comments ; Ibid., 1895, p. 422. 



