128 MY NATURE NOTEBOOK. 



is just as good to eat, from the insects' point of view, 

 as it is beautiful from ours, and the saplings always 

 have a hard struggle for existence. The entomolo- 

 gist knows this well, and never passes a young white 

 poplar without scanning its branches for the many 

 curious caterpillars which are seldom to be found on 

 other trees if there is an abele near at hand. It is 

 one of the most striking phases of instinct that a 

 mother moth, who never eats leaves, and has probably 

 no recollection whatever of having eaten them as a 

 caterpillar, should exhibit all the knowledge of a 

 botanist in choosing, out of a whole wood, to lay her 

 eggs upon the exact variety of poplar which her 

 caterpillar children will like best. She will never see 

 them. Probably she has no notion that anything 

 will ever come out of her eggs. So far as one can 

 tell, she never intentionally looks at the eggs after 

 she has laid them ; and if she happens to be a 

 prisoner in a confined space she will lay one egg 

 upon the top of another without compunction, some- 

 times glueing a score or more into a lump, from 

 which one would think that the baby caterpillars 

 in the middle must have a lot of worry in emerging. 



CATERPILLAR PESTS. 



But the interesting instinct of the mother moth 

 in selecting exactly the right kind of tree for the 

 caterpillar children that she will never see, becomes 

 a decided nuisance when you also have selected 

 exactly that kind of tree for ornamental purposes. 

 Thus, in a "good year" for insects, your young abeles 

 are often reduced to very rags and tatters. Among 



