GENERAL DEVELOPMENT OF THE TRUNK FROM STAGE K TO THE CLOSE OF EMBRYONIC LIFE, pp. 361-377.
_External epiblast._--Division into separate layers. Placoid scales. Formation of their enamel. _Lateral line._--Previous investigations. Distinctness of lateral line and lateral nerve. Lateral nerve a branch of vagus. Lateral line a thickening of epiblast. Its greater width behind. Its conversion into a canal by its cells assuming a tubular arrangement. The formation of its segmental apertures. Mucous canals of the head. Their nerve-supply. Reasons for dissenting from Semper's and Götte's view of lateral nerve. _Muscle-plates._--Their growth. Conversion of both layers into muscles. Division into dorso-lateral and ventro-lateral sections. Derivation of limb-muscles from muscle-plates. _Vertebral column and notochord._--Previous investigations. Formation of arches. Formation of cartilaginous sheath of notochord and membrana elastica externa. Differentiation of neural arches. Differentiation of hæmal arches. Segmentation of cartilaginous sheath of notochord. Vertebral and intervertebral regions. Notochord.
DEVELOPMENT OF THE SPINAL NERVES AND OF THE SYMPATHETIC NERVOUS SYSTEM, pp. 378-396.
_The spinal nerves._--Formation of posterior roots. Later formation of anterior roots. Development of commissure uniting posterior roots. Subsequent development of posterior roots. Their change in position. Development of ganglion. Further changes in anterior roots. Junction of anterior and posterior roots. Summary. _General considerations._--Origin of nerves. Hypothesis explaining peripheral growth. Hensen's views. Later investigations. Götte. Calberla. Relations between Annelidan and Vertebrate nervous systems. Spinal canal. Dr Dohrn's views. Their difficulties. Hypothesis of dorsal coalescence of lateral nerve cords. _Sympathetic nervous system._--Development of sympathetic ganglia on branches of spinal nerves. Formation of sympathetic commissure.
DEVELOPMENT OF THE ORGANS IN THE HEAD, pp. 397-445.
DEVELOPMENT OF THE BRAIN, pp. 397-407. General history. _Fore-brain._--Optic vesicles. Infundibulum. Pineal gland. Olfactory lobes. Lateral ventricles. _Mid-brain._ _Hind-brain._--Cerebellum. Medulla.--Previous investigations. Huxley. Miklucho-Maclay. Wilder. ORGANS OF SENSE, pp. 407-412. _Olfactory organ._--Olfactory pit. Schneiderian folds. _Eye._ General development. Hyaloid membrane. Lens capsule. Processus falciformis. _Auditory organs._--Auditory pit. Semicircular canals. MOUTH INVOLUTION and PITUITARY BODY, pp. 412-414. Outgrowth of pituitary involution. Separation of pituitary sack. Junction with infundibulum. DEVELOPMENT OF CRANIAL NERVES, pp. 414-428. Early development of 5th, 7th, 8th, 9th and 10th cranial nerves. Distribution of the nerves in the adult. _The fifth nerve._--Its division into ophthalmic and mandibular branches. Later formation of superior maxillary branch. _Seventh and auditory nerves._--Separation of single rudiment into seventh and auditory. Forking of seventh nerve over hyomandibular cleft. Formation of anterior branch to form ramus ophthalmicus superficialis of adult. General view of morphology of branches of seventh nerve. _Glossopharyngeal and vagus nerves._--General distribution at stage L. Their connection by a commissure. Junction of the commissure with commissure connecting posterior roots of spinal nerves. Absence of anterior roots. Hypoglossal nerve. MESOBLAST OF HEAD, pp. 429-432. _Body-cavity and myotomes of head._--Continuation of body-cavity into head. Its division into segments. Development of muscles from their walls. General mesoblast of head. NOTOCHORD IN HEAD, p. 433. HYPOBLAST OF THE HEAD, pp. 433-434. The formation of the gill-slits. Layer from which gills are derived. SEGMENTATION OF THE HEAD, pp. 434-440. Indication of segmentation afforded by (1) cranial nerves, (2) visceral clefts, (3) head-cavities. Comparison of results obtained.