320 



THE NATURALIST. 



insect, and the supposition was that 

 such an opening could not be made 

 unless the threads were cut ; but 

 that, however, has already been 

 proved to be a mistake. From 

 France the insect has been brought 

 into England. The experiment of 

 its acclimatization was first tried by 

 Lady Dorothy Nevill, at Dangstein, 

 near Petersfield, Hampshire. In 

 the autumn of 1863 (with a view to 

 a similar experiment), some Ailan- 

 thus were planted in the garden at 

 Sheriff Hutton Park ; and in the 

 spring, two w^ere set in pots in the 

 greenhouse, as it seemed not un- 

 likely that the worms might do 

 better on the living tree than on 

 sprays gathered and placed in water, 

 which was the method usually 

 adopted. My wish of making the 

 experiment (of how far the climate 

 of this part of England might suit 

 these silkworms) becoming known 

 to Lady Dorothy Nevill, she very 

 kindly made me a present of two 

 dozen newly hatched worms, which 

 reached Sheriff Hutton Park at 

 half-past seven o'clock on the morn- 

 ing of June 30th. They were tirst 

 supplied with fresh gathered leaves, 

 and, within two hours, 23 were 

 placed on one of the plants in the 

 greenhouse; the other worm, though 

 alive when the letter was opened, 

 died shortly afterwards. In this 

 situation they throve satisfactorily, 

 making changes, the description of 



which, by Mons. F. Blain (in a 

 little publication entitled *' Le ver 

 a sole de I'Ailante et son education 

 en Anjou," is so accurate that I 

 prefer using it, to attempting one 

 of my own. One little omission, 

 however, I must supply in its place. 

 "The first age is the interval which 

 passes from birth to the first change ; in 

 this age the young caterpillar is blackish., 

 and its length is about four millimetres 

 (about one-sixth of an inch ) The sec(md 

 age is that which separates the first change 

 from the second. The body of the cater- 

 pillar at that time is yellow, with the 

 head, the points of the segments, and the 

 tubercles black. It measures from eight 

 to ten millimetres long; and in the third 

 age the body is from fifteen to seventeen 

 millimetres long, it is soon covered with a 

 waxy substance, quite white, intended to 

 shield it from the rain." 



Mon^. Blain has omitted to notice 

 that at this age the tubercles grow 

 into (as it were) pyramids, or, rather, 

 obelisks, each one capped with a 

 black spot, the insect presenting a 

 more singular appearance than it 

 does at any other time. While in 

 the greenhouse three worms unac- 

 countably disappeared, twenty only 

 remaining for the open air experi- 

 ment. On Friday, 15th July, the 

 plant was taken, with the worms on 

 it, from the greenhouse, and placed 

 under the Ailanthus in the garden 

 (which, as a safeguard against birds, 

 had been netted over), and the silk- 

 worms soon dispersed themselves 

 over the trees. The change from 

 a heat of upwards of 70 degrees to 

 a low summer temperature seemed 



