128 THE ENTOMOLOGIST. 



The larvae were received on the 8th of June, and were then 

 about from half to three-quarters of an inch in length; and 

 were divided for experiment into three parties, of which one 

 was placed in a succession vinery of which the air was very damp 

 (the grapes being then at the stage in which the house required 

 frequent syringing) ; and the temperature was always genial, but 

 variable, as it was raised by sun-heat, but not artificially, excepting 

 occasionally by warm air admitted from the next house. Another 

 party of larvse was placed in a room of which the window was 

 closed at night, where the temperature was about 60° to 64° ; and 

 the remainder in a large garden-loft where the windows and door 

 were open da)' and night, and the larvge were consequently exposed 

 to draughts of air and a much lower temperature, the lowest noted 

 being 48°. The rate of growth of the "worms" varied according 

 to the warmth of the air and its general suitableness for their 

 health. On the 17th of June — that is, nine days after they were 

 received— those in the warm and damp vinery were grown, in the 

 most advanced instance, to 2f in. ; those in the room to If in., 

 and those in the draughty loft to about If in. ; all the larvae 

 having been treated alike in matters of food. On June 21st the 

 vinery larvse were 3 in. long, those in the house about 2^ in., and 

 those in the loft 1^ in. By June 2:3rd numbers of the vinery 

 caterpillars were spinning ; of those in the house two began to 

 spin on June 26th, but the mass did not spin for some days later; 

 the caterpillars in the draughty loft did not begin to spin until 

 July 6th. 



The worms varied in condition as well as rate of growth, 

 those in the vinery being plump, soft, and warm to the touch, 

 and appearing as if in active brisk enjoyment of their lives ; 

 those in the house were firmer and harder ; and the loft cater- 

 pillars had a cold, dead feel ; they all, however, appeared healthy, 

 and I had very few losses — which I conjectured was from the 

 method of feeding; but not understanding silkworm management 

 I cannot say with certainty. 



The worms were fed by placing good-sized sprays (about 

 a foot or a foot and a half long), just cut from the mulberry-tree, 

 upright in large pots or boxes (or any convenient receptacle) 

 of earth. The creatures fed eagerly on the leaves, and not 

 having to move about on a defiled surface were thus kept per- 

 fectly free from contact with anything that might soil their 



