Noteworthy differences exist between the two lives with respect to the influence of habit. Everything in the animal life is under the dominion of habit. Habit dulls sensation, habit strengthens the judgment. In the organic life, on the contrary, habit exercises no influence. The difference comes out clearly in the development of the individual. The organs of the organic life attain their full perfection independently of use; the organs of the animal life require an education, and without education they do not reach perfection (_Loc. cit._, p. 127). Bichat was the founder of what was known for a time as General Anatomy--the study of the constituent tissues of the body in health and disease. His classification of tissues was macroscopical and physiological; he relied upon texture and function in distinguishing them rather than upon microscopical structure. The tissues he distinguished are as follows:--[38] 1. The cellular membrane. 2. Nerves of animal life. 3. Nerves of organic life. 4. Arteries. 5. Veins. 6. Exhalants. 7. Absorbents and glands. 8. Bones. 9. Medulla. 10. Cartilage. 11. Fibrous tissue. 12. Fibro-cartilage. 13. Muscles of organic life. 14. Muscles of animal life. 15. Mucous membrane. 16. Serous membrane. 17. Synovial membrane. 18. The Glands. 19. The Dermis. 20. Epidermis. 21. Cutis. 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 vegetal_, p. 41, Paris, 1907. [10] _Exercitationes de generatione animalium_,1651. For an account of Harvey's work on generation and development, see Em. Radl'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, foetum, perfectionem in singulis acquirit." [12] See I. Geoffroy St Hilaire, _Essais de Zoologie generale_, p. 71, Paris, 1841. [13] M. Foster, _Lectures on the History of Physiology_, Cambridge, p. 53, 1901.