12 



the changes it undergoes are larger in amount, relatively to its- 

 size, and therefore more measurable, than those of any part of the 

 external anatomy, subject as the latter is to the restraining effect 

 of environment. 



Colour and Pattern. 



The RUTELINJE, while they include many species, iu India and 

 elsewhere, which for beauty and brilliance of colouring can scarcely 

 be excelled, are less generally characterised by bright combinations 

 of colour than the CETONIIUJE. Regarded as a whole their colours 

 are simple and, in their natural environment, inconspicuous. 

 Certain large groups, like the ADORETINI and an important part 

 of the great genus Anomala, which are nocturnal in their habits, 

 are of dull brown or yellowish shades, and many of the remainder, 

 which in all probability frequent and feed upon foliage by day, 

 are of various shades of green in harmony with their surroundings. 

 The chief exceptions to this are found in the PABASTASILNT, which 

 from morphological evidence already mentioned, may be safely 

 pronounced to be neither nocturnal nor foliage-frequenting. 

 Amongst these are Indian species of bright red hue (2'arastasia 

 sulcipennis), sharply contrasted scarlet and black (P. alternata), 

 and jet-black with strikingly conspicuous orange markings (P. 

 rufopicta, P. basalis, etc.). The conclusion seems irresistible that 

 these insects, unlike most other EUTELIN^E, aim at conspicuous- 

 ness and not at concealment. I believe it will be found that the 

 members of this group are generally unpalatable, while the rest 

 are for the most part relished by birds and insectivorous animals. 

 Probably certain species of ANOMALINI with sharply contrasted 

 colours are also unpalatable. A number of Indian species, like 

 Mimela fulgidivittata, M. leei, and 3/. horsfieldi, Anomala auronitens 

 and A. pteryyophorus, and Callistopopillia iris, are striped with 

 fiery-red and golden bunds upon a brilliant green background, 

 and others, like Macropopillia arrowi, Anomala princeps, A.flavo- 

 picta and many more, show sharp contrasts of orange and black 

 or green. 



Among the nocturnal ADOKETINI, while the colouring is almost 

 uniformly dingy, a number of species have a more or less com- 

 plicated pattern produced by the manner of distribution of the 

 fine setae with which the surface is clothed. This is a very 

 interesting phenomenon, the meaning of which is quite unknown. 



When writing, in the previous volume, of colour and pattern 

 in the CETONIIN^E, I referred to the wide limits of variation in 

 those features and their unreliability for the discrimination of 

 the species. This is perhaps even more true of the KUTELIN^E, 

 as is seen in such extraordinarily variable insects as Anomala 

 polymorpha and A. transversa, Popillia discalis, and many other.- ; 

 but another fact of equal importance emerges rather strikingly 

 from the study of the present subfamily, namely, the great 

 significance of types of coloration as indications of the natural 



