INSTRUCTIONS IN LEPIDOPTERA. 19 



vain to examine the dense portions, it is equally vain to dig 

 at the roots of trees in such localities, and you will rarely find 

 anything unless upon trees of considerable growth ; the thick 

 moss which collects about the trunks and roots is the part 

 to be examined. Bombyces are generally found under the 

 moss which covers spreading roots and not on the trunks, 

 which seem to be preferred by the Geometi-ce. The best 

 localities in woods are the borders or open places ; such 

 places when elevated or facing the north are generally the 

 most productive. Hedge-rows it is perfectly useless to try; 

 why it should be so, I cannot tell. The only instrument I 

 use is a common garden trowel ; the form is immaterial, 

 perhaps a rounded blade is best, as passing with greater ease 

 between the roots. The trees which I have found the most 

 productive are the following, — elm, oak, ash, poplar, beech, 

 willow and alder. In digging, it must be borne in mind 

 that all pupae are close to the trunk of the tree, seldom more 

 than two inches distant; frequently the trunk of the tree forms 

 one side of the cocoon, especially the cocoon of such insects 

 as spin ; the chrysalis also lies almost invariably close to the 

 surface of the earth. Insert the trowel about three inches 

 from the trunk, to the depth of two inches or so ; then push 

 it to the tree and turn up ; if the soil be dry and friable, 

 without grass, knock it gently with the trowel, which will be 

 sufficient. If, however, there be grass you must proceed 

 more cautiously ; take up the sod on the left hand, knock it 

 very gently with the trowel, and those pupae which merely 

 enter the ground will drop out; to find those which spin, 

 you must carefully examine the sod, tearing the roots of the 

 grass asunder; these are of course much the most difficult 

 to find, the cocoons being generally of the colour of the 

 earth. It is useless to try sticky or clayey grounds, the 

 caterpillars being unable to penetrate it ; in searching under 

 moss the best plan is to loosen the edge, then to tear it gently 



