206 HUXLEY AND NATURAL SELECTION 



Wallace, on the wings of a large proportion of the indi- 

 viduals of Kallima. Here, too, further investigation has 

 shown greater detail in the resemblance. The markings 

 which represent the largest patches of cryptogamic growth 

 bear a black central column composed of tall, upstanding 

 scales. When the patch is photographed slightly magnified, 

 under oblique illumination, the character of the scales is 

 well shown, together with the pronounced shadow cast 

 by the column. 1 These tall, black scales doubtless repre- 

 sent, in form as well as in colour, the fructification in the 

 centre of a patch of leaf-attacking fungus, perhaps the 

 very kind which at a later stage of development produces 

 the holes suggested by the ' windows ' on another part 

 of the wing surface. 2 



Hence it is seen that recent research into this long- 

 known resemblance to dead leaves has brought out many 

 new details, but only such as add to and strengthen the 

 old descriptions and support the old interpretation. The 

 likeness to leaves is shown to be even more remarkable 

 and more detailed than was at first supposed, but not 

 a single new fact suggests that the appearance serves any 

 purpose except protection from enemies in the struggle for 

 life, or hints at any cause of evolution except accumulation 

 by the survival of the best-concealed individuals through 

 innumerable generations. 



Some Seasonal Changes in Butterflies and their 

 Significance, 



The fact that there are well-marked differences between 

 the wet season and the dry season broods of certain butter- 

 flies has been known for many years. Among the most 

 characteristic of these is the tendency of the apex of the 

 fore-wing to be much elongated and bent, or some- 

 times even hooked, in the dry season. Almost equally 

 marked is the greatly produced anal angle of the hind- 

 wing at the same season of the year. These characters 

 have been recently observed to be conspicuous in the 

 Indian Kallimas of the dry season, which are also larger 



1 Exhibited upon the screen, 



2 Proc. Ent. Soc, Lond., June 7, 1905. 



