172 



TEXTILE FIBRES. 



The cocoon is about the size of a plum, and nearly similar in shape to 

 that fruit. The larva or caterpillar is about two inches in length when 



full grown. The annulations or joints of 

 the larva are about seventeen in number, 

 spongy in form, with tufts of stellate 

 hairs. 



Fig. 113 shows three of the fibres of 

 Antheraea mylitta with a longitudinal 

 groove running down * the centre. The 

 groove does not actually separate the two 

 portions of the fibre. 



The illustration is a photo- micrograph 

 of three silk fibres of A. mylitta as seen 

 under the quarter-inch power of a good 

 microscope. 



The two outer coatings of most silk 

 fibres are specially adapted for absorbing 

 brilliant dyes : the fibres are tenacious and 

 glossy, and lend brilliancy to the surface 

 or face of silk fabrics. 

 The Tussur silkworm chiefly feeds on the leaves of the Terminulia 

 tomenlosa. The leaves of the plant are elliptical, acute, with a pinnate 



Fig. 111. Cocoons of Bombyx 

 mori and of Cricula trifene- 

 strata. 



Fig. 112. Cocoons of Anthereea mylitta. 



venation. They grow in tufts at the ends of the stalks; hence the name 

 of the genus, Terminalia. The Tussur silkworm also feeds on Ter- 

 minalia Catappa, a broader-leaved species with obovate leaves, blunt 



