29G ALBERT KUNTZ 



terminates in the region of the genital ridges, in a slender cellular 

 cord which Remak has called the intestinal nerve (Darmnerv). 



This ganglion was described by Onodi ('86) and by His, Jr. 

 ('97), but, as far as I have been able to learn, no worker before me 

 has traced the cells composing it to their source. My prepara- 

 tions show conclusively that the cells giving rise to the ganglion 

 of Remak are derived directly from the anlagen of the hypogas- 

 tric plexus. In transverse sections through the posterior sacral 

 region, where the mesentery is broad and the rectum lies close 

 to the anlagen of the hypogastric plexus, cells may be traced from 

 the latter directly into the ganglion of Remak (figs. 5 and 6). 



The ganglion of Remak has no counterpart in mammals. It 

 may be of interest to note at this point that an examination of 

 several embryos of the turtle (kindly placed at nry disposal by 

 Dr. F. A. Stromsten, of these laboratories) has shown that while 

 there is no well defined ganglion in this type, corresponding to the 

 ganglion of Remak, there are numerous cell-aggregates associated 

 with the rectum, which evidently constitute the prototype of 

 Remak's ganglion. It is probable, therefore, that this ganglion, 

 so enormously developed in birds, is correlated with oviparous 

 habits. 



4- Vagal sympathetic plexuses 



(a.) Introductory. — In an earlier paper I have shown that in 

 mammals the sympathetic plexuses related to the vagi; viz., 

 the cardiac plexus and the sympathetic plexuses in the walls of 

 the visceral organs, have their origin in cells which migrate from 

 the vagus ganglia and the walls of the hind-brain along the fibers 

 of the vagi. I have, therefore, designated these plexuses as the 

 " vagal sympathetic" plexuses. My observations on embryos of 

 the chick show clearly that in birds also these plexuses have 

 their origin in cells which migrate from the hind-brain and the 

 vagus ganglia. 



(b.) Myenteric and submucous plexuses. — Inembryosof thechick 

 in the 130-hour stage, the vagus trunks may be traced posteriorly 

 along the walls of the oesophagus just a little below its ventral 



