20 



STRUCTURE OF THE LEP1DOPTERA 



the same time marked with delicate transverse lines. Others are 

 beautifully pitted or honeycombed, some ornamented with the 

 most faithful representation of fine wicker-work, while a few are 

 provided with a cap, more or less ornamental, that is raised by the 

 young larva when about to see the world for the first time. A few 

 of these beautiful forms are here illustrated and named, and another 

 has already appeared on page 14, but an enthusiastic young 

 naturalist may easily secure a variety of others for his own 

 examination. 



It may be surmised from the accompanying illustrations that 

 the form of the egg is always the same for any one species. 

 This is really the case, and consequently an experienced entomo- 

 logist can often decide on the name of the butterfly or moth that 

 deposited a cluster of eggs he happens to find in his rambles and 

 searchings ; but in such decisions he is always greatly assisted by a 



FIG. 11. EGG OF 

 THE MEADOW 

 BKOWN BUTTER- 

 FLY. 



FIG. 12. EGG OF 

 THE SPECKLED 

 WOOD BUTTER- 

 FLY. 



FIG. 13. EGG OF 

 THE VAPOURER 

 MOTH. 



knowledge of the food plants of the various insects, and sometimes 

 also by the manner in which the eggs are arranged. 



We have seen that the period during which the Lepidopt&ra 

 remain in the egg stage is very variable, and depends largely on 

 the season in which they were laid ; but it is often possible to tell 

 when to expect the young larvae by certain changes which take 

 place in the appearance of the egg. As the horny covering of 

 the egg is transparent, the gradual development of the cater- 

 pillar from the clear fluid can be ^watched to a certain extent ; but 

 if you have a microscope, and would like to witness this develop- 

 ment to perfection, proceed as follows. 



Arrange that some butterflies and moths shall lay their eggs on 

 strips of glass of convenient dimensions for microscopic work -three 

 inches long by one wide is the usual size for this kind of work. 

 This is easily accomplished by placing a proper selection of female 

 insects in a rather small box temporarily lined with such ' slips.' 

 When a few eggs have thus been secured, all you have to do is 



