GOAT MOTH. 209 



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

 wood should be inclosed with them. No farther trouble is re- 

 quired; for as they eat the dry wood, and do not need to be sup- 

 plied daily with fresh food, as is the case with the leaf-eating cater- 

 pillars, 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 sjDecimen 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 silk-worm, save that the muscles 

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

 comparatively smaller. Toward the head, however, a pair of or- 

 gans 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 part of each of 

 these proceeds a delicate thread, which the microscope shows to 

 be hollow ; and which is, in fact, a duct leading into the mouth. 

 These sacs contain a very foetid 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 

 skill and perseverance. Still, 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. 



Another moth belonging to the same family is also a notable 

 borer into wood. This is the pretty insect called the "Wood- 

 leopard Moth (Zeuzera cesculi), a rarer moth than that which 

 has just been described, though not by any means a scarce insect 

 when the entomologist knows when and where to look for it. 



The larva of the Wood-leopard Moth is rather pretty in color, 

 being whitish-yellow, spotted regularly with black, and having a 



O 



