Note 52 — PART I.—MORPHOLOGY AND PHYSIOLOGY (continued 8)

The word grès we translate as the layer of gum. Not sure of the English equivalent for grès, I applied to Dr. L. O. Howard, U. S. Entomologist, who kindly answers as follows: “I have consulted Mr. Philip Walker, a silk expert, who writes me the following paragraph: ‘Grès, as I understand it, is the gum of the silk fibre, hence the French name for raw silk, grèye, which is in distinction to the silk that has been boiled out in soap after twisting, or throwing, as it is called. As I understand it, the silk fibre is composed of the grès and fibroin. The former is soluble in alkali, like soap water, and the latter is not.’” While Blanc considers the grès as the product of a special secretion of the wall of the reservoir, Gilson regards its production as simultaneous with that of the silk or of the fibroin (l.c. 1893, p. 74).