The Origin of the Markings of Caterpillars. 239 



from this localization of the spots supposing it to 

 be of general occurrence it becomes of importance 

 to institute observations with different broods, so 

 as to investigate their first appearance, frequency, 

 and local limitation. It appears to me very pro- 

 bable that, with respect to frequency and time of 

 appearance, there would be great differences, since, 

 in the last stage, it is just this character which shows 

 a great variability. It would be more remarkable 

 if it should be established that the first appearance 

 of the spots was always limited to a certain seg- 

 ment ; and there would then be a great analogy 

 with the first appearance of the eye-spots in 

 Chcerocampa and the ring-spots in Deilephila. 



Fifth Stage. 



The adult caterpillar does not differ in marking 

 to any considerable extent from the preceding 

 stages. The first and last stripes do not appear 

 larger than the intermediate ones, as the latter 

 now increase in size. Many specimens were 

 entirely without red spots ; in others they were 

 present, but were small and inconspicuous, whilst 

 in others again there were two spots, one above 

 the other, of a vivid ferruginous red, these 

 coalescing in some cases, and thus forming one 

 spot of a considerable size. I have never seen 

 these spots formed into a regular, linear, coloured 

 border to the white oblique stripes as occasionally 

 happens in TY/z^-^-either in living specimens, 

 blown larvae, or in figures. 



