CHAPTER XIII. GENERAL CONCLUSIONS. Pp. 331-388.✦

I. Mode of origin and homologies of the germinal layers, pp. 331-360. Formation of the primary germinal layers, pp. 332, 333. Invagination, pp. 333-335. Delamination, pp. 335-338. Phylogenetic significance of delamination and invagination, pp. 338-345. Homologies of the germinal layers, pp. 345, 346. The origin of the mesoblast, pp. 346-360.

II. Larval forms: their nature, origin, and affinities. Preliminary considerations, pp. 360-362. Types of larvæ, pp. 363-384. Phylogenetic conclusions, pp. 384, 385. General conclusions and summary, pp. 385, 386.

PART II. ORGANOGENY;✦

INTRODUCTION. Pp. 391, 392.✦

CHAPTER XIV. THE EPIDERMIS AND ITS DERIVATIVES. Pp. 393-399.✦

Protective epidermic structures, pp. 393-397. Dermal skeletal structures, p. 397. Glands, pp. 397, 398.

CHAPTER XV. THE NERVOUS SYSTEM. Pp. 400-469.✦

The origin of the nervous system, pp. 400-405. Nervous system of the Invertebrata, pp. 405-414. Central nervous system of the Vertebrata, pp. 415-447. Spinal chord, pp. 415-419. General development of the brain, pp. 419-423. Hind-brain, pp. 424-427. Mid-brain, pp. 427, 428. General development of fore-brain, pp. 428-430. Thalamencephalon, pp. 430-435. Pituitary body, pp. 435-437. Cerebral Hemispheres, pp. 437-444. Olfactory lobes, pp. 444, 445. General conclusions as to the central nervous system of the Vertebrata, pp. 445-447. Development of the cranial and spinal nerves, pp. 448-466. Spinal nerves, pp. 448-455. Cranial nerves, pp. 455-466. Sympathetic nervous system, pp. 466-468.