The Origin of the Markings of Caterpillars. 249 



or brownish-black, and again, from reddish-brown 

 to lilac (Fig. 3), this last being the rarest 

 colour. 



The designation " polymorphism JJ may here 

 appear very inapplicable, since we have no sharply 

 distinct forms, but five very variable ground- 

 colours connected by numerous intermediate modes 

 of coloration. Should, however, the term " vari- 

 ability" be suggested, I am in possession of an 

 observation which tends to show that the dif- 

 ferent colours have to a certain extent become 

 fixed. I found a brown caterpillar, the five front 

 segments of which were light green on the left 

 side, and the fifth segment brown and green 

 mixed (Fig. 9, PI. III.). Such parti-coloration can 

 evidently only appear where we have contending 

 characters which cannot become combined ; just as 

 in the case of hermaphrodite bees, where one half 

 of a segment is male and the other half female, 

 the two characters never becoming fused so as to 

 produce a truly intermediate form. 38 From this 

 observation, I conclude that some of the chief 



38 [Figures of a remarkable case of gynandromorphism in 

 a butterfly (Cirrochroa Aoris, Doubl.) have recently been 

 published by Prof. Westwood (Trans. Ent. Soc. 1880, p. 113). 

 On the right fore and hind- wings of a male specimen there are 

 patches of female colouring, thus bearing out in a very striking 

 manner the above views concerning the non-fusibility of 

 characters (in this case sexual) which have been long fixed. 

 Complete (/. e. half-and-half) gynandromorphism is not un- 

 common in butterflies. R.M.] 



