1. The cellular membrane.12. Fibro-cartilage.
2. Nerves of animal life.13. Muscles of organic life.
3. Nerves of organic life.14. Muscles of animal life.
4. Arteries.15. Mucous membrane.
5. Veins.16. Serous membrane.
6. Exhalants.17. Synovial membrane.
7. Absorbents and glands.18. The Glands.
8. Bones.19. The Dermis.
9. Medulla.20. Epidermis.
10. Cartilage.21. Cutis.
11. Fibrous tissue.

The "cellular membrane" seems to mean undifferentiated connective tissue; "exhalants" are imperceptible tubes arising from the capillaries and secreting fat, serum, marrow, etc.; the "absorbents and glands" are the lymphatics and the lymphatic glands.

In Bichat's eyes this resolution of the organism into tissues had a deeper significance than any separation into organs, for to each tissue must be attributed a vie propre, an individual and peculiar life. "When we study a function we must consider the complicated organ which performs it in a general way; but if we would be instructed in the properties and life of that organ we must absolutely resolve it into its constituent parts."[39] The tissues have, too, a great importance for pathology, for diseases are often diseases of tissues rather than of organs.[40]

[9] Le Monde végétal, p. 41, Paris, 1907.

[10] Exercitationes de generatione animalium, 1651. For an account of Harvey's work on generation and development, see Em. Rádl's masterly Geschichte der biologischen Theorien, i., pp. 31-8, Leipzig, 1905.

[11] The passage runs:—"Sic natura perfecta et divina nihil faciens frustra, nec quipiam animali cor addidit, ubi non erat opus, neque priusquam esset ejus usus, fecit; sed iisdem gradibus in formatione cujuscumque animalis, transiens per omnium animalium constitutiones (ut ita dicam) ovum, vermem, fœtum, perfectionem in singulis acquirit."

[12] See I. Geoffroy St Hilaire, Essais de Zoologie générale, p. 71, Paris, 1841.

[13] M. Foster, Lectures on the History of Physiology, Cambridge, p. 53, 1901.

[14] Zootomia democritea, Nuremberg, 1645; Antiperipatias, seu de respiratione piscium, Amsterdam, 1661.

[15] Rádl, loc. cit., i., p. 50.