THE VICTOKIAX NATURALIST. 115 



walking this larva moves very slowly, and this, coupled with its 

 conspicuous marking, would render it an easy prey to birds, etc. 

 But to guard against extinction the larva has been provided 

 with eight rays or tufts of fine spines placed on small protuber- 

 ances — four on the two first segments and four on the two last. 

 These rays lie in small grooves when the larva is at rest, but at 

 the least shake given to the tree on which it feeds they are 

 raised ready for attack, and as they are capable of inflicting a 

 sting quite equal to that of the English nettle, they may be 

 reasonably supposed to be protected from the attacks of birds, 

 ichneumons, etc. I believe this larva is very little troubled by 

 birds, but it has enemies amongst the Hemiptera, as I often find 

 one of the wood bugs sucking the juices of the larva. 



The ichneumons also kill numbers, but not in the larval 

 stage. They appear to know that they are well protected, and 

 therefore wait until they turn to pupa, in which they deposit 

 their eggs ; which, on hatching, find at once food and shelter 

 very much at their host's expense. I may safely state that six 

 out of every twelve are destroyed by ichneumons, and if the 

 larvae were not protected from the attacks of birds, it would 

 soon become very rare, or perhaps extinct. There appears to 

 be some doubt as to whether the poison is injected into the 

 wound through an opening in the spines. Under the 

 microscope it will be seen that the spines are hollow, and con- 

 tain a brown fluid, but I could not find any opening to let this 

 fluid enter a wound caused by one of the spines. On the 

 points, and as far as the shoulder of each spine, they are covered 

 by a coating of glutinous substance, which, I think, is the 

 irritant matter. It will be noticed by those naturalists who 

 have made the life histories of our lepidoptera a study that 

 there exists a relation between the ichneumons and the larva 

 on which they deposit their eggs. That is, the perfect 

 ichneumons deposit their eggs in that kind of larva in which 

 they themselves passed the first part of their life. 



Some larvae depend for their protection on their colour and 

 form. Among the larvae of the Geometrinoe it will be seen that 

 they greatly resemble in colour the twigs of the tree or plant on 

 which they feed, and this resemblance is also helped by the 

 peculiar way in which the larvae hold themselves when alarmed. 

 They grasp the branch with the two last or anal feet and hold 

 themselves in a position so as to resemble a twig, and this 

 deception is also helped by two horn-like projections on the 

 first and fourth segments which some of these larvae possess. 

 So closely do some of these larvae match the plants on which 

 they live that it is very difficult to discover them, especially 

 one that lives on the sheoak {Casiiarina sp.). This larva is 

 green, and each segment is marked like one of the oak needles, 

 having the joints and markings exactly represented. It is also 



