“The cocoons of wild silk-worms are so strong and compact, that the insects encounter great difficulty in extricating themselves, and therefore remain inclosed from the end of the summer, to the spring of the following year. These butterflies, unlike the domestic insect, fly very well.--The domestic silk-worm is but a variety of the wild species. It is fed on the leaves of the mulberry tree.” (See chap. VIII.) The circumstance that the worms were sometimes fed with oak-leaves is mentioned in Du Halde’s History of China, vol. ii. p. 363. Here then we have a justification of the ancients in asserting, both that the silk-worms produced _long threads and webs floating in the air like those of spiders_, and that they fed upon the leaves of the oak, the ash, and many other trees. It may be recollected, that Pliny expressly mentions both the oak (_quercus_) and the ash (_fraxinus_). Until very lately the use of silk among the ancients was investigated only by philologists. Within a few years M. Latreille, an entomologist of the highest distinction, has directed his attention to the subject and has examined particularly the above-cited passages of Aristotle, Pliny, and Pausanias[60]. He never supposes the ancient Sericum to have been the produce of anything except the silk-worm. But of this there are several varieties, partly perhaps natural, and partly the result of domestication. He endeavors to explain some parts of Pliny’s description by showing their seeming correspondence with some of the practices actually observed by the Orientals in the management of silk-worms. [60] M. Latreille’s paper is published in the Annales des Sciences Naturelles, tome xxiii. pp. 58-84. An account of the wild silk-worms of China is to be found in the “Mémoires concernant l’Histoire, les Sciences, les Arts, &c., des Chinois,” compiled by the missionaries of Peking[61]. This account is principally derived from the information of Father D’Incarville, one of the missionaries. It coincides generally with the accounts already quoted from Du Halde and Breton. We extract the following particulars as conveying some further information: [61] Tome ii. pp. 579-601. Paris, 1777, 4to. This Memoir is reprinted with abridgments as an Appendix to Stanislas Julien’s Translation of the Chinese Treatise on the Breeding of Silk-worms, Paris, 1837, 8vo. “The Chinese annals from the year 150 B. C. to A. D. 638 make frequent mention of the great quantity of silk produced by the wild worms, and observe that their cocoons were as large as eggs or apricots.”