LEPIDOPTERA. 95 



quickly commence to feed, while the keepers are always on the watch to protect 

 them from insect-vermin, birds, etc., which, if permitted, would soon clear off 

 the whole plantation. Forty-five days at the outside, and the larvae are full-fed ; 

 they then spin their cocoons, pass into the pupa state, and the winding oft* of the 

 silken harvest begins. The largest cocoons are selected and set aside for the 

 breeding of larvae for another year. The rest are exposed to a high temperature 

 which destroys the pupae within. Boiling water — in which the earthy salts of 

 buckwheat ashes cleaned for this purpose have been dissolved — renders the cocoon 

 fit for being unwound. The silk is wound off in strands, — five, six, or eight in 

 number, — a single strand from each cocoon, according to the strength of thread 

 required. The silk thus prepared is much stronger than that from the silk-worm 

 moth, though it is neither so fine in texture nor so valuable. The Japanese oak 

 silk-moth (S. yama-mai) is closely allied to the above, and the process of culti- 

 vation of the insect much the same. 



The Silk-Spinners, — Family BombyciDjE. 



The only species belonging to this family known in Europe is the one 

 mentioned above as the true silk-worm moth {Bomtibyx mori). This insect has 

 become acclimatised in many parts of Southern Europe, where, as in China, it 

 is cultivated for its silken produce. The larva is itself not remarkable, save 

 perhaps for its resemblance to the caterpillars of the hawk-moths, with its smooth 

 naked skin, and short erect tail. It is, however, by far the most valuable 

 caterpillar yet discovered. Ages ago, from two to three thousand years before 

 the Christian era, — if Chinese records be reliable, — this larva was well known in 

 the far East, and already silk-culture was a well-established element in the 

 national industry. History relates how the eggs were first brought to Europe, 

 in the reign of the Emperor Justinian, by Persian monks, concealed in their 

 hollow bamboo staves ; and from these silk-culture in Europe took its origin. It 

 was, at any rate, carried on at Constantinople in A.D. 520. The Arabs introduced 

 the industry into Spain, whence it spread in the twelfth century to Sicily, and 

 thence to Italy and all the south of Europe. So far as England is concerned, 

 both James I. and George I. endeavoured to introduce the cultivation of the silk- 

 worm for commercial purposes, but without success. The actual mode of cultiva- 

 tion and preparation of the cocoon differs in no very essential feature from that 

 of the oak silk-moth, save that it is usually conducted under cover in well- 

 ventilated rooms; the wicker trays of silk- worms being arranged in rows one 

 above the other on light bamboo racks. 



The Hawk-Moths, — Family Sphingidje. 



The large moths included in this family are either diurnal or subnocturnal 

 in their habits, flying powerfully both in the daytime or just before nightfall. 

 Amongst other characteristics, the antennae are gradually thickened towards the 

 tip, which terminates in a hook. The fore-wings are elongate, narrow, and usually 

 pointed towards the apex ; while the hind-wings are comparatively of small size. 



