32 MONTHLY JOURNAL OF AGRICULTURE. 



nine thousand fold ! From this period, and during the whole of its t^vo succeeding states of 

 being, the worm inibihes no nourishment, iuid gradually diminishes in weight ; being sup- 

 poited by its own substance and appearing to find suflicient occupation in fonning its silken 

 Web, and providing successors fjr our gei-vice, without indulging that grosser appetite which 

 forms the beginning and the end of their desires during their caterjiillar existence. 



The moth enjoys its liberty for only a brief space. Its first employment is to seek its mate ; 

 after which the female deposits her eggs; and both ui the course of two or three days after, 

 end their beuig. 



" FoRMATio>f OF Silk.'' By M. H. Straus, of Durckheira. — " It is generally admitted by 

 natm-alists that the thread of the caterpillar is produced by a simple emission of litpiid matter 

 thi'ough the orifice of the spuuier, and that it acqviii-es soliditv- at once from the drying in- 

 fluence of the air. It was easy to entertain such an hypothesis, for nothing is more simph; 

 than the Ibrmatiou of a very fine thread by such a process. But a little reflection will soon 

 show us, even a priori, that it is not possible ; for h'>w can we comprehend that so fine a 

 fibre, liquid at the uisl;mt of its issue from the apertiu'e, should instan'ly acquire such a con- 

 fiistence as to bear the weight of the animal suspended by it, and at the same time tliat it is 

 rapidly produced ? Though the fluid, holduig the silk in solution, should be quickly vola- 

 tilized, it must still be a matter of conjecture, how the animal suspended by his thread could 

 be able to arrest its issue, holding on only by the thread itself, for it caimot pinch the thread, 

 seeing that it is only in a liquid state inside, and the thread caimot be glued to the edge of the 

 openuig, as its rapid adhesion would prevent its issue while the animal is spinning. A little ex- 

 amination would satisfy us that silk caimot be produced in this manner, but that it is secreted 

 TO. \he form, of silk m. ihe silk vessels, and that the spinning apparatus only winds it. The 

 thread is produced in the slender posterior part of the vessel, the uiflated portion of wliich 

 consists of the reser\-oir of ready fonned silk, where it is found ui the fonn of a skein; each 

 thread being rolled up so as to occupy in the silk-wonn {Bombex mori) a space of only about 

 a sixth part of the real length of the skein. The fact is shown by the following experi- 

 ment I made for the puq)ose of ascerteiining whether the silk is fonned in the body of the 

 caterj)illar8 : 



" Take one of the animals when about to form its cocoon, clean it in common vinegar, in 

 which it may remain from foiir to six honrs, open it on the back and extract the silk vessels, 

 there beimr one on each side of the alimentary canal. Take them np by the hinder end, just 

 where they begin to swell (Jarlher back the silk is not solid enough J, and draic them, out. The 

 membrane forming the vessel is easily torn open, and the contents expand to six or seven times 

 its original length. Ttic skein ha,vin^ attained its full length by the letting out of its gathers, 

 we obtain a cord perfectly equal in size throughout except at the end, tchere it is attetntated. 

 Tliis cord resembles a large horse-hair, and constitutes what fishermen call " i^/ore«ce hair." I 

 ought to add that in simply drawing out the silk vessel, the Florence hair is found enveloped in a 

 golden yellow gummy matter, formnig the glutinous portion which the worm fastens its thread. 

 This must be got rid of by drawing the cord through the fold formed on the inside of the joint of 

 the left fore-finger, converted into a canal by applying to it the end of the thumb. The glutinous 

 substance and the membranes being thus separated we have the naked hair. In this state, be 

 fore the silk becomes dry and hard, not only will it be indefinitely divided loneitudinally, which 

 proves its fibrous structure, but in trying to split it by drawing it transversely, the little filaments 

 oj silk which form it are perfectly separated, making a bundle of cctremely fine fibrils." 



For some beautiiul lines, " The Silk Woi-m's WiU," see the Housewife's Department. 



COST AND PROFIT OF CULTIVATING CORN AND COTTON: 



I PERCEIVE that a good deal has been lately said in Massachusetts about the cost 

 of growing Indian corn, and am not a little surprised to find the expense of culti- 

 vating an acre set down by some at |50. I presume a large quantity of maimre 

 is used, at an extravagant price. Others estimate the expense at $6 to $7 per 

 acre. This must be where no manure is used. 



I have thought it miglit not be without interest to some of your readers to 

 know what it costs us to grow both corn and cotton here in South Carolina, and 

 to be enabled to fortn some idea of the profits of our farmni'j;. Livuig about the 

 middle line of the State, and cultivating light upland which produces crops about 

 the average of those of this Slate, and I may add, 1 think, of Georgia, I will tell 

 you what, / /a/oir, are the expenses and prolits of Agriculturo here. 



On land ?;j ^ood heart, without more manuring than to haul out and put on the 

 poor spots what we make, I may say casuatly, and can spare from our gardens 

 and potato patches, Ave consider it a very fair average crop to gather from an 



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