Abstract
In the esophagus of Formosan macaque, no esophageal glands could be found existing. The tunica muscularis is striated nature in the upper part of the esophagus but comes to be replaced by smooth musculature in the lower part, and in the lowermost 1/6, the muscularis entirely consists of sheer smooth musculature.
The nerve fibres coming into the esophagus form the periesophageal plexus provided with small ganglia in its adventitia.
AUERBACH's plexus in the upper part of the esophagus of this animal is very ill developed, but in the mid-part and below it considerably gains development. The ganglion cells forming the ganglia in the plexus were found to be of DOGIEL's Type I and of apolar or infantile type, no DOGIEL's Type II cells being ever found. The ganglia of MEISSNER's plexus are better developed in the upper than in the lower part of the esophagus and contain cells usually of infantile type but sometimes of DOGIEL's Type I.
The vegetative fibres distributed in the esophagus comprise very fine sympathetic fibres and somewhat thicker parasympathetic fibres, and forming terminal reticula (STÖHR) as their terminations, come into control by contact over the tissue cells supplied, as in the case with man and the other animals studied hitherto.
The motor fibres supplied to the striated muscle tissue of the esophagus of the Formosan macaque end either in grape-like terminations prevalent in the human esophagus or quite as often in motor end-plates that are in predominance in the caprine esophagus. From this we may infer that the macaque stands just mid-ways between man and goat in this respect.
The sensory fibres supplied to the esophagus of the macaque consist in thicker fibres than motor fibres and form their terminations in all the layers of the esophagus.
In the tunica muscularis are found unbranched and simple branched sensory terminations, particulary often in the intermuscular connective tissue septa. Their fibres usually are smooth surfaced thick ones frequently changing size and show more or less conspicuous glomerular arrangement. Their terminal areas contain a few specific cell nuclei. Branched terminations composed of terminal fibres showing no looping in their courses, however, were not rare either. Besides some branched terminations are formed by side branches sent out from the stem fibres into the tunica muscularis in their courses toward the submucosa. It is of deep interest that branched terminations ending after running winding courses specific to sensory fibres are found in the striated muscle tissue in the upper esophagus.
Rather complex branched terminations are found in the ganglia of AUERBACH's as well as MEISSNER's plexus. In these, the many branch fibres show conspicuous change in size, run looped courses and spread out over rather large areas, ending in blunt or sharp points. It is of special interest that terminations in glomerular arrangement are not rare, either.
Unbranched and simple branched sensory terminations of fibres running conspicuous snake-like courses are found in the submucosa.
Unbranched and simple branched terminations were found in the lamina propria mucosae, too, but here the courses of the terminal fibres are not very wavy, the fibres ending in sharp points just beneath the epithelium. No intraepithelial fibres were ever found in the esophagus of the monkey.
The sensory terminations formed in the esophageal wall of the Formosan macaque described above are inferior in structure to those in man, but generally superior to those in dog, goat and snapping turtle.
