Vegetable and Animal 



The camel is not indigenous in Australia, and one can 

 only trust that the' kangaroo is so foolish as not to be 

 able to pick out the nutritious Loranthus leaves from 

 amongst the astringent acacia foliage. 



The resemblance of some insects when at rest to a leaf 

 or a stick is most remarkable. This is an old story, and 

 in every sense, for it was Commerson in the eighteenth 

 century who first called attention to the exact leaf-like 

 pattern of some of the creatures found by him. More- 

 over, an insect apparently allied to our cockroaches 

 existed in the Carboniferous period, whose wings in the 

 shape and veining closely copy the leaflets of a common 

 fossil (Neuropteris) of that time. 3 



There is a difficulty often brought up against the 

 usual theory about such mimetic resemblances, which is 

 that in the early stages, before the similarity was perfect, 

 they could not possibly be of any use. That objection, 

 however, is not so much felt by field naturalists as by 

 those who conduct their inquiries in a public library. 



In going through the dry, yellowish-brown grass near 

 Lake Albert Edward Nyanza, I rose a grasshopper-like 

 creature which alighted on a withered grass haulm and 

 was at once invisible. Its mode of resting aped exactly 

 the hang of the withered spikelets, and the colour of such 

 part of its wings and legs as were exposed were pre- 

 cisely that of the withered vegetation. 



Such incipient colour resemblances and imperfect 

 mimicries are very abundant. 



A far more important point, however, is the close 

 and intimate relation which exists between animals and 

 plants when considered as diners and dinners. 



It is not often realised how greatly the animal world 

 stimulates and improves the vegetation. It is not only 

 man that can make two blades of grass develop where 

 only one had grown before. Worms which feed upon 



197 



