Human thyrothymic venous connections were more numerous in pre-natal life. The thymus was vascular since the 10th week. At 11 weeks, nerves invaded the capsule and a few trabeculae. At 16 weeks, nerve bundles accompanied arteries and veins. Their branches ran close to intralobular arterioles and venules. Parenchymal nerves appeared in the cortex and medulla. Radial cortical capillaries drained into capsular venules at 20 weeks. From 28 weeks pre-natally to 3 years post-natally, nerves in the medulla ended in knobs or fine tapers. Some encircled or relayed on HassalΓs corpuscles. Others were traceable to blood vessel walls. The pattern of innervation and vascularization was not altered up to 9 years. The vasculature began to be irregular at 11–13 years. Parenchymal and perivascular nerves existed up to 15 years. At 25 years, nerves were detected in the capsule and proximal parts of the trabeculae.

The cricothyroid muscle in dogs received branches from two independent nerves, namely the external ramus of the cranial laryngeal nerve and the pharyngeal branch of the vagus. Classical spindles are infrequent in the muscle. Atypical forms of sensory endings were identified. Two end-plates were frequently met with on a single extrafusal fibre. Sectioning of the external ramus of the cranial laryngeal nerve was followed by degeneration of spindles. Intact axons detected up to 6 months after operation are probably derived from the pharyngeal branch of the vagus. Chromatolytic changes occurred in the ipsilateral dorsal vagal nucleus and the capsulated ganglion at the entry of the nerve into the muscle. Chromatolysis occurred in the intramuscular ganglion cell rows and in neurons of the ipsilateral nodose ganglion. Morphological alterations were more pronounced in the ipsilateral medial column of the nucleus ambiguus. No changes were observed in the somata of the mesencephalic nucleus.

The innervation of extra-ocular muscles of albino mice, aged 1, 10, 20, 30 annd 120 days, was studied in serial sections cut in the three main planes. Some orbits were fixed in Bouin's and others were fixed in a mixture of: 5% potassium dichromate, 5% mercuric chloride and 5% potassium chromate. All sections were stained with Holmes' silver stain. The following nerve endings were described:( a ) Preterminal nerve fibers parallel to the muscle fibers end in 1-3 motor endplates in several muscle fibers and others form several en grappe end-plates on one muscle fiber. Unipolar nerve cells were seen along the nasociliary nerve. Harder's gland was innervated by a peri-acinar plexus which sent nerve fibers between the cells as nerve endings. The significance of the findings was discussed.

The adrenal glands of four rats from each of the following age groups, newly born and one-, two-, three-, five-, seven-, nine-weeks-old were used. Sections 15 fi in thickness were cut and stained with hematoxylin and eosin, Holmes, Bodian and Bielschowsky methods to show nerve fibers and cells in the gland. At birth the nerve fibers extended from beneath the capsule to the central part of the gland where collections of various neurons were found. After one week, nerve cells (which probably belonged to parasympathetic) were found in the inner part of the fasciculata while the adrenal medulla contained nerve cells which belonged to the two sets of autonomic nervous system. By the end of two weeks a fine plexus of nerve cells and fibers was found in inner fasciculata. In the three-week-old rat adrenals the plexus of nerve cells and fibers extended to the zona reticularis. By the age of five weeks the plexus was present in the inner fasciculata as well as in the reticularis. The clusters of sympathetic and parasympathetic ganglion cells were a constant feature of the medulla. By the end of seven and nine weeks the intrinsic adrenal plexus was a principal feature of the zona reticularis. The functional significance of the profuse intrinsic nerve supply of both the cortical and medullary portions of the gland is discussed.Although the adrenal gland has a profuse nerve supply a definite nerve supply to the cortical portion has not been generally accepted. Previous investigators found that nerve fibers traversed the cortex to end in the medulla. Kiss ('51), Lever ('53) and ('55), however, observed few nerve endings in relation to cortical cells. Mikhail ('61c) described a fine plexus of nerve cells and fibers in the zona reticularis and inner fasciculata in the adrenals of some adult mammals. The latter believed that the presence of such a plexus is an indication of the importance of the inner zones in the functional activity of the gland. However, in newly born and immature rats the reticularis is absent. A study of the adrenal plexus in the rat throughout post natal life was thought to be essential in order to establish the recent view that, irrespective of their appearance, the inner parts of the gland are the most important functionally.Although innervation of the medulla is generally accepted further study is needed to determine the contribution of the inner zone plexus to the medullary cells. Therefore, this investigation was carried out to ANAT. REC., 152: 431-438 study the intrinsic nerve supply of both parts of the gland during post natal life. MATERIAL AND METHODSMale albino rats from the same strain were used in this investigation. Four rats from each of the following age groupsnewly born, one-, two-, three-, five-, seven-, nine-weeks rats were used to study the intrinsic nerve supply of the gland. The animals were killed by ether and their adrenals were quickly removed and cleared of fat. One gland was fixed in Bouin while the other was fixed in formol saline or formol, alcohol acetic mixture. After f...

The modes of division and branching of the extrapetrous part of the facial nerve and the presence or absence of communications between its branches and between it and the trigeminal nerve and cervical plexus were studied in nineteen mammalian species. Communications between the facial and derivatives of the mandibular division of the trigeminal were found invariably, but were inconstant in the case of the two other divisions and of the cervical plexus. The possible functional significance of the observations is discussed.