194 ENTOMOLOGICAL NEWS. [October, 



in good condition, and from these, with the assistance of a silk 

 manufacturer in the neighborhood of Philadelphia, he succeeded 

 in raising a few worms, which formed their cocoons in July. 



Toward the middle of August the moths made their appear- 

 ance, and the eggs laid by them hatched their worms from Au- 

 gust 3oth to September 3d. Some of these were placed by Dr. 

 Stewardson on a tree in a private garden; some were set out on 

 trees in the suburbs, and others were fed by him in a room at 

 his house. Of the first lot, nearly all came to maturity; many 

 of those placed in the country were destroyed by birds, and about 

 forty cocoons were secured from those raised in the house. The 

 success with the worms placed on the trees, except for the attacks 

 of birds, was entirely satisfactory, and proved to the experi- 

 menters, apparently, the possibility of raising two crops of the 

 insect during the proper season if reasonable care were taken to 

 preserve them from injury. 



On the appearance of the first crop of caterpillars in the Spring 

 or early Summer of 1862, Dr. Stewardson was still sufficiently 

 interested in them to supply them with food, but the work was 

 becoming irksome. As Corresponding Secretary of the Academy, 

 most of his leisure time was spent in the room in the northeast 

 corner of the building, which was then situated at Broad and 

 Sansom Streets, and now forms part of the Lafayette Hotel. 

 My duties as Assistant Librarian placed me in constant commu- 

 nication with the doctor, and I became intensely interested in his 

 caterpillars, their growth and their work. I was, therefore, de- 

 lighted when the opportunity was given to me to take charge of 

 them and look after their allowance of Ailanthus leaves. The 

 supply was abundant, and fresh, crisp leaves were placed in glass 

 jars in the Librarian's room as often as a change was necessary. 

 The work was continued during the fall of 1862 and the Spring 

 and Summer of 1863. In the Autumn of the latter year I began 

 the study of chemistry with Dr. Robert E. Rogers, in the Uni- 

 versity of Pennsylvania, preparatory to matriculating as a student 

 of medicine. My time was then so occupied that it was increas- 

 ingly difficult to look after my pets, which, in spite of the fact 

 that not all of the successive broods had been preserved, num- 

 bered at the time some hundreds and required constant attention 

 to save them from starvation. 



The yard of Dr. Roger's laboratory, at the back of the Medi- 



