THK CALIFORNIA 



lected at this critical period, they assume in due time 

 the chrysalis form, but for want of sufficient strength 

 leave incomplete their silken tomb. 



Many persons have erroneously imagined that li^ht 

 is injurious to the silkworm ; but the very reverse of a 

 belief so contrary to nature, is evidently true. In its 

 native state, it is of course habituated to the most per- 

 fect light ; indeed, a due proportion of the reviving 

 light of day has been found essentially necessary to its 

 perfect health. In the perfect light of day, when the 

 sun shines, the leaves of the mulberry and other trees 

 inhale vital air, or that pure, etherial substance, which 

 by being inhaled, gives life and heat to the animal sys- 

 tem ; while in the darkness, they evolve mephitic air, 

 which is destructive and incapable of affording nourish- 

 ment. 



Although the silkworm will endure a great degree of 

 heat, yet when this heat is combined with excessive 

 moisture, the effect appears to be at least as deleterious 

 to the insect as mephitic air. If a silkworm be con- 

 fined in a close vessel, surcharged with moisture and 

 heated to eighty-eight or ninety degrees, it will soon 

 reject food and show strong symptoms of distress ; 

 the muscles will soften, and evaporation will become 

 obstructed ; the power of contraction, which resides in 

 the skin, and which governs the secretions, which are 

 indispensably necessary to its existence, will cease, and 

 it will shortly perish ; while a warm-blooded animal, if 

 sufficiently supplied with pure atmospheric air, will 

 endure an equal degree of heat, combined with an 



