336 DIRECT BENEFITS DERIVED FROM INSECTS. 



Transactions of 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 Psydium pornifirum and pt/riferur,i ovate 

 nests of caterpillars eight inches long-, of gray silk, which 

 the inhabitants of Chilpancingo, Tixtala, &c. in Ame- 

 rica, manufacture into stockings and handkerchiefs''. 

 Great numbers of similar nests of a dense tissue, re* 

 sembling Chinese paper, of a brilliant whiteness, and 

 formed of distinct and separable layers, the interior 

 being- the thinnest and extraordinarily transparent, 

 were observed by Humboldt in the provinces of Me- 

 choacan and the mountains of Santarosa at a height of 

 10,300 feet above the level of the sea, upon the Arbu- 

 tus Madrono and other trees. The silk of these nests, 

 which are the work of the social caterpillars of a Bom- 

 byx {B. Madrono^ H.), was an object of commerce even 

 in the time of Montezuma, and the ancient Mexicans 

 pasted together the interior layers, which may be writ- 

 ten 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 

 colour*^. And according to M. B. de Lozieres, large 

 quantities of a very beautiful silk, of dazzling- white- 



^ Pullpir in Phil. Trans. 1759. 54- " Jntnb of Boiunt,; ii. iOl. 



'" Polilical Essay on N. i^pain, iii. 59. 

 " Voyage dans VAmcr. ?laitl. i. '^l^. 



