DIRECT BENEFITS DERIVED FROM INSECTS. 225 



barrel to the stock ; but as far as Colonel Sykes could ascertain, no use 

 is made of the silk in Western India, though there can be little doubt that 

 it might be advantageously produced, as the caterpillars which spin it feed 

 indiscriminately on the Teak tree {Tectona grandis), the Mulberry 

 (^Morus Lidica), the Bor {Zizyphus jujuha), and the Osana (Terminalia 

 alata glabra).^ 



Other species, as may be inferred from an extract of a letter given in 

 Young's Annals of Agriculture^, are known in China, and have been 

 introduced into India. " We have obtained," says the writer, " a monthly 

 silk-worm from China, which I have reared with my own hands, and in 

 twenty-five days have had the cocoons in my basins, and by the twenty- 

 ninth or thirty-first day a new progeny feeding in my trays. This makes 

 it a mine to whoever would undertake the cultivation of it." 



Whether it will ever be expedient to attempt the breeding of the larvae 

 of any European moths, as Catocala pacta, Sponsa, he. proposed with 

 this view by Fabricius^, seems doubtful, though certainly many of them 

 afford a very strong silk, and might be readily propagated ; and I have 

 now in my possession some thread more like cotton than silk spun by the 

 larva of a moth, which when I was a very young entomologist I observed 

 (if my memory does not deceive me) upon the Euojiymus, and from the 

 twigs of which (not the cocoon) I unwound it. It is even asserted that 

 in Germany a manufacture of silk from the cocoons of the emperor moth 

 (^Saturnia Pavonia major) was at one time established.^ There seems 

 no question, however, that silk might be advantageously derived from 

 many native silk-worms in America. An account is given in the Philo- 

 sophical Transactions o^ one found there, whose cocoon is not only heavier 

 and more productive of silk than that of the common kind, but is so much 

 stronger that twenty threads will carry an ounce more.^ Don Luis Nee 

 observed on Psidium pomiferum and pyriferum ovate nests of caterpillars 

 eight inches long, of grey silk, which the inhabitants of Chilpancingo, 

 Tixtala, he, in America, manufacture into stockings and handkerchiefs.® 

 Great numbers of similar nests of a dense tissue, resembling Chinese 

 paper, of a brilliant whiteness, and formed of distinct and separable layers, 

 the interior being the thinnest and extraordinarily transparent, were observ- 

 ed by Humboldt in the provinces of Mechoacan and the mountains of 

 Santarosa, at a height of 10,500 feet above the level of the sea, upon the 

 Arbutus Madrono, and other trees. The silk of these nests, which are 

 the work of the social caterpillars of a Bombyx (B. Madrono), was an 

 object of commerce even in the time of Montezuma ; and the ancient 

 Mexicans pasted together the interior layers, which may be written upon 

 without preparation, to form a white glossy pasteboard. Handkerchiefs 

 are still manufactured of it in the Intendency of Oaxaca.^ De Azara 

 states that in Paraguay, a spider, which is found to near the thirtieth degree 

 of latitude, forms a spherical cocoon (for its eggs) an inch in diameter, of 

 a yellow silk, which the inhabitants spin on account of the permanency of 

 the color.^ And according to M. B. de Lozieres, large quantities of a 



' Trans. Boyal Asiat. Soc. 1834. vol. iii. « xxiii. 235. 



5 Vurlesungen, 325. * Latr. Hist. Nat. xiv. 150. 



5 Pnllein in Phil. Trans. 1759, 54. e Annals of Botany, ii. 104. 



^ Political Essay on N. Spain, iii. 59. 



^ Voyage dans VAmer. Merid. i. 212. It may here be observed as a benefit derived by the 



