282 On the Culture of ^S'/Z/r. 



and visible movement of systole and diastole, and yet not any vestige 

 of a respiratory organ has been detected in it for the admission of 

 atmospheric air vvhich could be put in contact with any internal part ; 

 for if the insect is opened or crushed, its fluids become sud- 

 denly discolored with black and purple tints : on the other hand, the 

 contrasts of light and darkness, and of heat and cold, which by con- 

 tinuation would impair the heahh and vigor of the silk-worm, do not 

 appear to possess any influence upon its vitality. That principle 

 therefore must emanate from the idioelectric nature of its body or of 

 the silk, of vi^hich it is never deprived ; but other demonstrative proofs 

 of that character are afterwards adduced. 



The second question arises from the great reproductive powers of 

 the Bombyx mori : Each female papillo being able to furnish nearly 

 five hundred fecundated eggs. Yet no sexual character could ever 

 be distinctly assigned to the male. The learned Abbe Sauvage, a great 

 practical silk culturist, gave up the problem, because, in an infinite num- 

 ber, of the larva he could trace by the scalpel, but one ovarium, indica- 

 ting only one sex; it would seem, however, that our author has unrav- 

 elled the mystery; (page 88, vol. I.) the sexual attribute is the last or- 

 ganic formation in the animal when its growth is completed, and when 

 it no longer requires food. The change of the ovarium, into vasti 

 deferentia is the first step to the state of chrysalis, as we find that in 

 spinning its silk, the male is at last recognized by the peculiar shape 

 of its cocoon. This alteration probably depends upon a greater de- 

 gree of vigor in one third portion of the whole brood, which will 

 thus suffice to fecundate the two others ; and in this last phasis, 

 although smaller than the female, the silk papillo is elegant in shape, 

 liveliness and activity ; so much so, that for its longer preservation, Dan- 

 dolo recommends to keep it in absolute darkness. This entomolog- 

 ical phenomenon is in this case the more credible, as it is necessary for 

 all insects subject to metamorphoses, that organs of reproduction, 

 should be substituted to those of alimentary digestion; the latter being 

 no longer required, are obliterated. 



The second volume embraces the practical instructions derived 

 either from the ancient and modern culturists, or from new theories 

 and proposed experiments. The author wishing to afford his reader 

 the means of judging and comparing, has condensed, in seventeen 

 precepts, the old method of rearing silk-worms, and such as prevail- 

 ed in Italy and France more than one hundred and sixty years ago ; 

 next he subjoins & diary of a recent system recommended by the Count 



