The Positive Sciences of the Ancient Hindus c9.s3.3

c9.s3.3

The ovum fertilised by the sperm-cell and developing under the influence of animal heat forms successive layers and tissues, even as layers of cells and fibres are formed in wood. First are formed seven layers, epithelial and dermal (*Saptatwachah*), then follow the several tissues (*Kalâh*), the flesh, the vascular tissue, the fat and marrow, the lymphatic and (glandular) tissue, the intestinal tissues, the biliary and the seminal vessels. These tissues are regarded by some as modifications of the original dermal layers of the ovum (*cf.* the layers of the blastoderm and their relation to the tissues in Embryology). The tissues are supposed to be developed successively, one out of another, by chemical action or metabolism (*pâka*), *e.g.* chyle is transformed into blood, blood into flesh, flesh into fat, fat into bone, bone (in reality, fat in the bones) into marrow, marrow into sperm-cell. The organs are next formed out of the tissues. The liver, gall-bladder (*kloma*), spleen, and lungs are referred to the blood; the intestines to the blood, lymph, and bile; the kidneys to the blood and fat; the testicles to the blood, lymph, and fat; the heart to the blood and lymph; and the tongue to the lymph, blood, and flesh. *Vâyu*, with the accompaniment of animal heat, impels the "currents" (*śrotâmsi*) in the system; *Vâyu* acting on the flesh gives rise to the muscles; and it is *Vâyu*, again, which, with the essence of fat (or marrow), produces the nerves, arteries, and tendons (Suśruta, *Śârîrasthâna*, Chap. IV., and *Sûtrasthâna*, Chap. XIV.).