30 



other scientists assert that flacherie is due to ferments and vibrioni 

 developing in the intestinal canal of the worm; other authorities main- 

 tain that the disease may exist independently of these. However, as 

 these micro-organisms, in the majority of cases, play a prominent part 

 in the development of flacherie, it is well to guard against them. 



The principal causes of flacherie are: (1) Eggs being spoiled through 

 careless preservation; (2) hereditary tendency; (3) overfeeding of 

 worms; (4) wet, sweating, dewy, and fermented leaf; (5) leaf sub- 

 merged in water or full of mud; leaf from a new plantation or from a 

 shaded spot, coarse leaf, or change of leaf; (7) lack of ventilation; 

 (8) excessive heat; (9) dust; (10) keeping worms too thick on trays; 

 (11) accidental deaths of worms from injuries, these putrefying, and 



the ferments thus created 



being communicated to 



other worms; (12) debilit3^ 



If these causes are avoid- 



FiG. 14.-Worm which died of flacherie, putrefying after qA flacherie is not likely to 

 death. (Redrawn from Pasteur. ) . . m 



invade a rearing. lo pre- 

 vent contagion eggs should be dipped in a solution of sulphate of 

 copper before being incubated; and in cleaning shelves and nets, wher- 

 ever a dead worm is seen, powdered sulphate of lime or copper should 

 be applied. 



Unlike the corpuscles of pebrine, the microscopic organisms, which 

 are probably the immediate cause of flacherie, remain alive from one 

 year to another, and the dust of a rearing room may contain them in 

 considerable quantities and become the means of infection. Hence, in 

 cases of flacherie, immediately after the rearing, the walls, shelves, and 

 all the implements should be washed in a solution of chloride of lime 

 or some other germicide, and the room should be fumigated with 

 sulphur. 



GATTINE. 



The external signs of gattine are indifference to food, torpor, dysen- 

 tery, and emaciation. It attacks the worm in the first ages, and is 

 especially manifested after a molt. Sometimes it is associated with 

 flacherie, and, in its incipient stage, is confounded with this disease. 

 Later the worm becomes extraordinarily emaciated and sufficiently 

 transparent to be mistaken for a mature larv^a. The hooks of the 

 prolegs are lengthened out and stronglv attach the worm to whatever 

 it touches. Meanwhile torpor creeps on and soon ends its life 

 (fig. 15). 



Worms having flacherie or gattine do not always die before mount- 

 ing into the brush, and if the disease has not entirely invaded the 

 organism they may even arrive at spinning. But instead of mounting 

 with the promptness and rapiditj^ of healthy worms, they stop hesi- 

 tatingly at the base of the brush, then begin slowly to mount, stopping 



165 



