GOAT MOTH. 189 



strokes should injure the caterpillar. To the ears of the searcher, 

 a few hlo-ws with a mallet on the chisel do not appear very for- 

 midable; hut to an animal inclosed in the wood the shock of 

 every stroke must he terrihle, on account of the sound-conducting 

 power of the substance in which it lies. 



When one or two of the caterpillars have been obtained, they 

 should be placed in a metal box, as their sharp jaws would soon 

 force a passage through a wooden prison, and a quantity of the 

 wood should be inclosed with them. No further trouble is 

 required ; for as they eat the dry wood, and do not need to be 

 supplied daily with fresh food, as is the case with the leaf-eatmg 

 caterpillars, they are quite content, and feed and grow nearly as 

 well as if they had been left in undisturbed possession of the 

 tree in which they were hatched. 



Should any of them die, or should a sufficient number be cap- 

 tured to spare a specimen or two, dissection should be employed, 

 in order to show a very peculiar structure, which is probably of 

 use in enabling the caterpillar to make its way through the 

 wood. When laid on its back, and opened, the general structure 

 of the interior resembles that of the silkworm, save that the 

 muscles are far more strongly defined, and the silk-producing 

 organs are comparatively smaller. Towards the head, however, 

 a pair of organs are seen, which at once arrest the attention. A 

 couple of membraneous sacs — something like the honey-bag of 

 the bee, only very much larger, and long in proportion to their 

 width — ^lie on either side of the neck, if we may so term the first 

 few segments of the larva. They are generally rather flaccid, so 

 that their sides are wrinkled longitudinally. From the upper 

 pai-t of each of these proceeds a delicate thread, which the micro- 

 scope shows to be hollow ; and which is, in fact, a duct leading 

 into the mouth. These sacs contain a very fcetid fluid, which is 

 supposed to moisten the wood, and partly to soften it, so that it 

 can be shredded with comparative ease. 



It is hardly necessary to refer the inquiring reader to Lyon- 

 nett's magnificent work on this subject, as the book is a model 

 of skiU and perseverance. StOl, books are chiefly useful as 

 guides, and not as substitutes for practical experience ; and 

 though the beautiful work just mentioned may be perfectly 

 familiar, it ought only to act as a guide to the investigator, and 

 not to supply the place of actual dissection. 



