[ 175 J 



126 



impregnated eggs produce no worms, and those imperfectly impreg- 

 nated, bear in them the seed of diseases which destroy the silkworm 

 in various stages of its existence. 



2d. When the room is too hot, (77° to 81°:) if the male delays 

 coupling, it loses much of the impregnating liquid. If united to the 

 female too soon, upon issuing from the cocoon, she has not time to 

 evacuate a superabundance of excrementitious fluid with which she is 

 loaded. She therefore becomes disordered, and the impregnating li- 

 quor of the male is weakened, by admixture with this matter of the 

 female; consequently, the eggs are imperfect. 



3d. Dampness prevents the eggs from drying, the embryo becomes 

 affected, and diseases engendered. 



4th. When the place, where the eggs were kept, or hatched, has 

 been or is damp, the slow and gentle evaporation of the matter con- 

 tained in the shell, by which it insensibly attains the state assigned to 

 it by nature, is prevented. 



5th. When the eggs are too thickly heaped together, they heat, 

 even at a low temperature, and the embryo becomes injured. 



No disease will occur, 1st. if the temperature of the place where the 

 moths are kept, be maintained between 68° and 75°. 2d. When the 

 apartments are dry. 3d. W^hen cloths on which the eggs are deposit- 

 ed, are not folded too much, and are hung on the frames which have 

 been described. 



2. Diseases from mismanagement of good eggs, and treatment of 

 very young woryns. 



1. When the embryo just verging to the worm state, in a moderate 

 temperature, is suddenly exposed to a much greater heat, its organs 

 become decomposed, and the shell of the worm will appear more or 

 less red, which is a certain sign of future disease. 



2. When, on the pointof transformation into the worm, the embryo 

 is suddenly exposed to a lower temperature; the damage is then pro- 

 portioned to the length of time the heat has acted upon the embryo. 



3. When silkworms being just hatched, are exposed to a higher 

 temperature than that in which they come forth, or the contrar}'^, 

 when the worms are exposed to a colder temperature than that in 

 which they come forth. 



II. Diseases from the bad air of the district in which Silkiaorms are 



reared. 



Low marshy places, and those in which the air is liable to stagnate, 

 are very liable to produce disease. The combination of heat and mois- 

 ture is death to them. On the contrary, it is universally agreed, that 

 high and dry places are not only peculiarly favorable to the growth 

 and health of the insects, but that the silk there produced by them, is 

 much preferable to that from worms reared in places less elevateri 



