9 o PHOTOGRAPHY FOR NATURALISTS. 



familiar forms of " protective " mimicry. The cater- 

 pillars of geometer moths, which, when disturbed, 

 resemble rigid twigs, form an interesting study ; so, too, 

 does the lappet moth, which resembles a withered leaf; 

 and the orange-tip butterfly, the under-surface of whose 

 wings resemble some of the umbelliferous plants. 

 Photographic work of this nature should always be 

 accompanied by a colour record. If this be carefully 

 done, and the relative values of the colours preserved in 

 the negatives, such work will have a high value. The 

 material in our own islands is practically inexhaustible, 

 the subject is popular and deeply interesting, the 

 photographic difficulties are insignificant, and the hand 

 illustrations which have hitherto done duty are some- 

 times inaccurate and almost invariably deceptive. 

 In the face of these facts one can only wonder at the 

 scarcity of workers. Perhaps the true solution is to 

 be found in the apathy of hanging committees. 



