9822 Entomological Society. 



worms. Of his first brood, 563 moths hatched between the 22nd of May and the 27th 

 of July ; of these 230 fertile pairs were obtained ; their eggs were laid from the 24th 

 of May to the 26th of July, and were 37,000 in number; the fiist larva from these 

 hatched on the 11th of June, spun up on the loth of July, and emerged on the 20th 

 of August. Of another batch of larvae, the eggs of which were laid on the 6th and 7lh 

 of June, the first hatched out on .the 23rd of June, spun up on the 20th of July, and 

 emerged as a moth on the 23rd of August, — an interval of thirty-four days, — which 

 spoken of in France as a very short period for the egg to develope into a cocoon, 

 whereas in this instance the change look place in twenty-eight days. Of his second 

 brood, 10) moths hutched between the 21st of August and the 21st of September; 

 thirty-six fertile pairs were obtained ; their eggs were laid from the 23rd of 

 August to the 7th of September, and were 3438 in number; the first larva 

 from these hatched on the 7th of September, the last on the li)t\i of September, 

 and the first would in two or three days from that time be undergoing the last 

 moult prior to spinning. Thus, owing to the extraordinary warmth of the 

 season, a second brood would be obtained, and, by commencing earlier in the 

 year than he had done, this might be made more certain ; indeed Lady Dorothy 

 Nevill had her second brood spun up in cocoon in September. The silk was for the 

 first forty-eight hours quite white ; it then became moist, especially at the lower end of 

 the cocoon (perhaps from some emission of the caterpillar), and the colour changed to 

 dirty gray. The larvx, cocoons and moths all seemed to be finer in this country than 

 in France, as if the soil and climate were more suitable ; and all that was now required 

 was machinery to wind the silk, which had not yet been done in this country, though 

 it had in France and Italy. Dr. Wallace considered the experiment a great success, 

 and thought the possibility of cultivating the silk-worm in this country was proved ; 

 ailanthiculture had one great advantage over the culture of the mulberry silk-worm, 

 inasmuch as a crop of silk might be obtained from the Ailanthus tree in its third or 

 fourth year, and in its tenth year it would be in full bearing, whereas it took from 

 twenty to twenty-five years to establish a plantation of mulberry-trees. I^ might be 

 roughly calculated that the trees might be planted at the rate of one to every square 

 yard, and one tree would yield fifty cocoons ; 1000 cocoons would produce 1 ft. of silk, 

 which might be estimated to be worth £l when spun: on the other hand, one boy 

 could attend to an acre of silk-worms, and all the manipulation of the worms might 

 be dune by women and children of ten years old, so that the expenses would be 

 trifling. 



Mr. Scudder mentioned that in America use had been made of the larvee of 

 Bombyx Cynthia to make from the silken matter contained withiu them the fine lines 

 by which fish-liooks were fastened. He also referred to the success of M. Trouvelot in 

 cultivating the oak-feeding Bombyx Polyphemus (see Zool. 9620), of which he had 

 brought over some cocoons for M. Guerin-Meneville. M. Trouvelot had found the 

 birds to be his greatest enemies. 



Mr. W. VV. Saunders said the Ailanthus would grow almost anywhere, and seemed 

 to prefer a stiff soil ; be had it growing on clay, and it had flowered, fruited and seeded. 

 With reference to Prof. Westwood's statement, at the previous Meeting, as to the com- 

 parative density and tenacity of Ailanthus, oak and elm, he remarked that the qualities 

 which made wood useful as timber were strength, elasticity and durability, and that 

 Ailanthus was a poor and insignificant wood, and, like all quick-growing woods, would 

 be useless as timber. 



