60 INSECT ARTIZANS AND THEIR WORK 



through the egg-shell straight into the substance 

 of the leaf without seeing the direct light of day. 

 Making its way from the lower to the upper cuticle 

 of the leaf, it begins its mine just under the cuticle. 

 It is then less than one twenty-fifth of an inch long, 

 and has no limbs. Its progress through the leaf- 

 material as it feeds appears to be accomplished by 

 the alternate contraction and expansion of the 

 swollen first three segments of its body. 



When full-grown the caterpillar has attained to 

 the length of one-fifth of an inch, and it has lost 

 its appetite. Not wishing to finish its career in 

 the interior of the leaf, it cuts a half-circular slit 

 in the cuticle, and crawls out. It then proceeds 

 to spin a little cocoon around itself, probably in 

 the angle at the base of a spine on the rose-stem, 

 where it changes to a chrysalis, and a few weeks 

 later issues as a delicate little moth. 



Other species of the genus Nepticula may be 

 found mining the leaves of oak (N. atricapitilla), 

 elm (N. viscerella and N. marginicolella), beech 

 (N. tityrella), birch (N. luteella and N. betulicolella), 

 hawthorn (N. oxyacanthella, N. perpygm&ella, N. 

 ignobilella, and N. atricolella), bramble (N. splendid-' 

 issimella), hazel (N. floslactella smdN. micro theriella), 

 and many other plants. 



The Laburnum Miner (Cemiostoma laburnella) 

 proceeds somewhat differently. " After leaving the 

 egg, the caterpillar makes a reddish-brown circular 

 dot, about one twenty-fifth of an inch in diameter ; 

 when this is complete it changes its first skin and 



