Adjustment of colour in various pupx, etc. 429 



this species which he had obtained from Populus alia, and 

 I was greatly struck by the remarkable lightness of its 

 tint. It was quite unlike any larva of the species I had 

 ever seen. Mr. A. H. Hanim informs nie that he has 

 also observed great differences in the depth of colour of 

 this larva according to tlie food-plant upon which it has 

 been found. It is highly probable therefore that this 

 species is also sensitive, and searching experiments upon 

 it are greatly neecied. 



This case and the last are of high interest, inasmuch as 

 no larva at all closely allied to these two species has yet 

 been shown to be sensitive to the colours of its environ- 

 ment. 



3. Amphidasis hetularia. Mr. A. H. Hamm tells 

 me that he has again and again observed in nature the 

 wide differences between the colours of this highly sensi- 

 tive larva upon various food-plants, and that the differ- 

 ences are invariably in the direction of concealment. Mr. 

 Hamm's experience in the field is so wide and his 

 powers of observation so keen that the strongest confirma- 

 tion is afforded to the observations recorded in my previous 

 paper (Trans. Ent. Soc. Lond.1892, pp. 359, 360). 



4. Eupithecia pimpinellata. Mr. Merrifield informs me 

 that Mr. Nicholson (of Lewes) has noticed that this larva 

 appears in two forms — reddish-brown and green — which 

 correspond to the two forms of the seed-heads of Pimpinella 

 saxifraga on which it feeds. Mr. Nicholson states that 

 the green larvae are nearly always found on the green heads 

 and the others on the brown. 



The power of colour adjustment is probably present in 

 a very high degree in the larvae of the genus, and numer- 

 ous carefully conducted experiments are much to be desired. 



5. Vanessa polychloros. I may also mention that a 

 pupa of this species which I found (July 1899) upon the 

 dark painted iron railing at the North Entrance Gate 

 of the Oxford University Museum, harmonised very per- 

 fectly with the surface from which it was suspended. 



6. Vanessa antiopa. In August 1897 I found several 

 living pupa3 of this species attached to fences, buildings, 

 etc., at the Hunt Club, Scarborough Heights, Toronto. I 

 specially noticed that there was a marked resemblance 

 to the environment. This was all the more noticeable 

 inasmuch as the colours differed very widely, some surfaces 

 being very dark and others very light. 



