2o8 AGRICULTURE AND FORESTRY. 



is thus prepared, the eggs are deposited on the branches about the 

 beginning of May, when the young leaves are making their appear- 

 ance. About 20 to 30 eggs are pasted on strips of paper which 

 are bound to the branches, so that the young worms when hatched 

 may find food and protection from the sun. Against rain they 

 protect themselves by creeping with wonderful quickness to the 

 ur»der-side of the leaves, whereas the old and heavy worms often 

 sufifer in violent storms. Their numerous enemies in the open air 

 are, besides insects (particularly ants), tree toads, rats and birds, 

 chiefly ravens. These are kept off, partly by painting the lower 

 parts of the trunk with a sticky substance, such as the root-slime 

 of Hibiscus Manihot — partly by scarecrows and rattles which hang 

 on a rope extending across the whole plantation, and are kept in 

 motion by a person who sits on a high roofed seat in the middle, 

 and watches over all. 



The development of the worm up to time of spinning takes about 

 sixty-four days. It is divided into five periods, the first two of ten 

 days each, the third and fourth of thirteen days, and the fifth and 

 last eighteen days. This time however is subject to modifications 

 of many kinds. With a high even temperature and rich food, it 

 can be reduced to fifty days, and contrariwise lengthened to eighty. 

 Each casting is preceded by a two or three days' sleep, during 

 which the worm sits motionless, holding fast by its hind feet and 

 raising its fore parts after the manner of the sphinx. 



The young worms, at hatching 7 mm. long, with reddish brown 

 feet, but otherwise yellowish green in colour with two long black 

 stripes, after the fourth casting have a length of 7 cm., and are 2 cm. 

 in circumference. They are then of a fine green colour, well 

 ringed, and on the back have two rows of warts, each of which 

 is furnished with blackish brown hairs. Gold-yellow stripes on 

 each side, on each of which are five silvery spots, breathing places, 

 separate the back from the belly. 



When the worm is ready to spin, a light brown liquid exudes, 

 and it becomes restless, does not raise itself up however, but draws 

 one or more oak leaves about it, spins them together over its head, 

 and fastens its cocoon to them. In making the cocoon, it first 

 weaves about itself a transparent net of fine yellow-green silk, 

 through wiiich it can be seen industriously spinning. After about 

 six hours the net is no longer transparent, and after six or eight 

 days the cocoon is completed. Meanwhile the green of the inner 

 web has lost its intensity and become only a greenish }'ellow on the 

 outside. The cocoons are firm and of a beautiful ellipsoidal form, 

 without shrinkage in the middle, and about three cm. long, and of 

 7 grammes weight. Without the chrysalis its weight is from 70 to 

 80 eg., while an empty cocoon of the Bombyx Mori is not half so 

 heavy. Ten pounds of cocoons yield about i kg. of reeled silk. 

 The top layer has a coarse thread of greenish yellow, but the 

 underneath has a fine greenish white silk which, after soaking in 



