THE LEAF ROLLERS AND THE LEAF MINERS 



309 



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being rather stocky and wide for its length; it feeds upon the 

 juicy tissues of the leaf and di\'ides, as it goes, the upper from 

 the lower surface of the leaf; and it teaches us, if we choose to 



look, that these outer walls 

 of the leaf are thin, colorless, 

 and paper-like. We can trace 

 the whole life history and 

 wanderings of the little crea- 

 ture, from the time when, as 

 small as a pin point, it began 

 to feed, until it attained its 

 full growth. As it increased 

 in size, its appetite grew larger 

 also, and these two forces 

 working together naturally en- 

 larged its house. When finally 

 the little miner gets its growth, 

 it makes a rather larger and 

 more commodious room at the 

 end of its mine, which to us 

 looks like the head of the 

 serpent; here it changes to a 

 pupa, perhaps after nibbling 

 a hole with its sharp little 

 jaws, so that when it changes to a soft, fluffy little moth with 

 mouth unfitted for biting, it is able to escape. In some species, 

 the caterpillar comes out of the mine and goes into the groimd 

 to change to a pupa. By holding up to the light a leaf thus 

 mined, we can see why this little chap was never obliged to clean 

 house ; it mined out a new room every day, and left the sweepings 

 in the abandoned mine behind. Mines of this sort are often seen 

 on the leaves of nasturtium, the smooth pigvN'^eed, columbine, 

 and many other plants. There are mines of many shapes, each 

 form being made by a different species of insect. Some flare 

 suddenly from a point and are trumpet-shaped while some are 

 mere blotches. The blotch mines are made, through the habits 

 of the insect within them; it feeds around, instead of forging 

 ahead, as is the case with the serpentine miners. The lar\'as 

 of beetles, flies and moths may mine leaves, each species hav- 



A serpentine mine in nasturtium 

 leaf 



