506 HOMES WITHOUT HASDB. 



leaf in various ways. They all, however, agree in one point, 

 namely, their gradual and regular increase in diameter. At their 

 origin, they are so small that the finest thread could hardly pass 

 through them, but in proportion as they increase in length they 

 increase in width, so that at their termination they are sometimes 

 the twelfth of an inch in width. 



These marks are the tracks made by very small larvse, which live 

 between the membranes of the leaves, and feed upon the paren- 

 chyma, or soft substance which lies between the two membranes. 

 They follow no rule in their meanderings, but traverse the leaf 

 in a variety of ways. Sometimes they never leave the edge, but 

 follow every little serration of the leaf with perfect accuracy. 

 Sometimes they form a kind of spiral, and sometimes they 

 wander irregularly over the whole leaf Generally, the insect 

 does not cross the track which it has once made, being diverted 

 from doing so by some wonderful instinct. There are instances, 

 however, where the insect has crossed its own track, not only 

 once, but several times. 



If the little gallery be opened at the widest extremity, one of 

 three things will be found. Sometimes there is a tiny white 

 grub, very much resembling the larva of certain beetles, and 

 having the rings which represent the thorax rather wider than 

 those which will afterwards be developed into the abdomen. As 

 the little creature is able to live between the membranes of a 

 leaf so thin as that of the rose or oak, it is evident, to the most 

 superficial observer, that the insect which will be developed from 

 it must be of very minute dimensions. 



The larva of all winged insects is very large in proportion to 

 the same insects when they have obtained their perfect form, 

 much of the substance being taken up by the wings. As a 

 natural consequence, it follows that the larger the wings, the 

 larger must be the grub, the size of the body being quite a 

 secondary consideration. In the present case, the larvae which 

 we are supposed to examine belong to the lepidopterous order, 

 in all of which insects the wings, when present at all, are of 

 great comparative size. If, then, the full-grown larva is so smaU 

 that it can lie concealed between the membranes of a leaf with- 

 out causing any conspicuous alteration in its outline, it is evident 

 that the perfect insect must be of almost microscopical minute- 

 ness. Accordingly, it has been found that the little moths which 



