378 ANNUAL REPORT OF NEW-YORK 



CHERRY. LEAVES. 



my yard without one of these worms ever appearing upon it; 

 whilst upon an ash tree standing beside this sassafras and not 

 three feet distant from it there has repeatedly been a family of 

 these worms. Certainly if the sassafras were the favorite food of 

 this species some of these worms would have been placed upon it. 

 They have also occurred upon ash trees in other parts of my 

 grounds, and upon no other tree have I ever met with them. Last 

 year on the 1 8th of July a dozen young worms were found in a 

 cluster upon the under side of a leaf of the ash tree above alluded 

 to, and upon an adjacent leaf of the same stalk w^re the shells 

 of the eggs from which these worms had come, resembling little 

 cups or hemispheres of clear glass. The eggs were in contact 

 with each other on the under surface of the leaf, and this leaf 

 had been partly consumed by the worms when they first came 

 from their shells. I continued to notice them daily for about a 

 week, when they all disappeared, probably mounting high into 

 the tree, and I could discover no traces of them afterwards. Upon 

 the fall of the leaves in autumn I was disappointed to find no 

 cocoons upon this tree; but upon a lilac growing against the side 

 of the house four rods distant two dozen cocoons occurred. The 

 worms which formed these cocoons could not have fed upon the 

 lilac without being discovered, and I could not avoid the conclu- 

 sion that they had been reared upon the ash tree, and when fully 

 grown had migrated to this bush, though in doing so they passed 

 several other lilac bushes, and selected this, perhaps, because 

 growing against the side of the house it would be less apt to be 

 visited by birds than those standing in the open yard. But this 

 precaution did not save them. The last winter being unusually 

 long and severe, our winter birds were obliged to forage more 

 assiduously than usual, and before spring every one of these 

 cocoons w^ere perforated and its inmate destroyed. In other 

 instances I have noticed these worms remaining till they were 

 mature, upon small sprouts of the ash where they could be 

 observed daily. From all these facts I am confident the ash is 

 their favorite food. But when ready to spin their cocoons it is too 

 lai)orious a task for them with their silken threads to tie the long 

 leiif stalks of this tree to the limbs from which they grow, and I 

 have very seldom known a cocoon to be placed upon this tree. 



