300 SILK-MOTHS. Chap. VIII. 



Silk-Moths. 



These insects are in several respects interesting to us, more 



especially because they have varied largely at early periods 



of life, and the variations have been inherited at corresponding 



periods. As the value of the silk-moth depends entirely on the * 



cocoon, every change in its structure and qualities has been 



carefully attended to, and races differing much in the cocoon, 



but hardly at all in the adult state, have been produced. With 



the races of most other domestic animals, the young resemble 



each other closely, whilst the adults differ much. 



It would be useless, even if it were possible, to describe all 

 the many kinds of silk-worms. Several distinct species exist 

 in India and China which produce useful silk, and some of 

 these are capable of freely crossing with the common silk-moth, 

 as has been recently ascertained in France. Captain Hutton 63 

 states that throughout the world at least six species have been 

 domesticated ; and he believes that the silk-moths reared in 

 Europe belong to two or three species. This, however, is not * 



the opinion of several capable judges who have particularly 

 attended to the cultivation of this insect in France ; and hardly 

 accords with some facts presently to be given. 



The common silk-moth (Bombyx mori) was brought to Con- 

 stantinople in the sixth century, whence it was carried into Italy, 

 and in 1494 into France. 64 Everything has been favourable for 

 the variation of this insect. It is believed to have been domes- 

 ticated in China as long ago as 2700 B.C. It has been kept 

 under unnatural and diversified conditions of life, and has 

 been transported into many countries. There is reason to 

 believe that the nature of the food given to the caterpillar 

 influences to a certain extent the character of the breed. 65 

 Disuse has apparently aided in checking the development of 

 the wings. But the most important element in the production 

 of the many now existing, much modified races, no doubt has 



63 ' Transact. Entomolog. Soc.,' 3rd Stanislas Julien. 



series, vol. iii. pp. 143-173, and pp. 6* See the remarks of Prof. Westwood, 



295-331. Gen. Hearsey, and others, at the 



64 Godron, ' De l'Espece,' 1859, torn. i. meeting of the Entomolog. Soc. of Lon- 

 p. 460. The antiquity of the silk-worm don, July, 1861. 



in China is given on the authority of 



