390 MABEL BISHOP 



It then turns abruptly toward the midhne and terminates in 

 connective tissue medial to the ganglion petrosum of the ninth 

 cranial nerve. In making this spiral turn around the vagus, it 

 also crosses the glossopharyngeal and. hypoglossal nerves dor- 

 sally. The model does not indicate a swelling of the sympa- 

 thetic trunk in the region of the vagus ganglion, but it is 

 undoubtedly the position of the superior cervical sympathetic 

 ganglion. The course of the sympathetic trunk just described is 

 perfectly normal, as figured by Streeter in Keibel-Mall ('12, part 

 2, fig. 103) and in figure 642 of KoUman's Handatlas ('07, part 

 2), In the teras, however, there is interpolated between this 

 long ganglionic trunk and the normal spinal nerves a shorter 

 sympathetic trunk extending from about the seventh spinal 

 nerve caudad (fig. 7). This is in direct connection with the 

 spinal nerves by typical rami communicantes on the one side 

 and on the other with the long sympathetic trunk by shorter 

 rami. How far below section 500 the sympathetic trunk ex- 

 tends I do not know, as these sections are not in my possession. 

 After having reached the ventral surface of the bodies of the ver- 

 tebrae, the lowest two of the median spinal nerves show a pro- 

 liferation of cells at the distal end of the growing nerve trunk 

 (fig. 20, s. 362). This presents a picture closely resembling the 

 development of the spinal ganglia of the normal sides and is in 

 harmony with the description given for normal development by 

 Kohn ('07) in the rabbit, and Streeter in human embryos. 



In the head. The otic, ciliary, sphenopalatine, and submaxil- 

 lary ganglia in the outer (normal) half of each head are clearly 

 demonstrable and conform to the descriptions given by Kuntz 

 ('13). They may be readily identified in figures 15, 16, 17, 19. 

 In the median region they are identifiable with much less cer- 

 tainty except the sphenopalatine ganglia. These are conspicu- 



Fig. 5 Median sagittal section of the same model as figure 4. This shows the 

 sculpturing of the inside wall of the conjoined rhombencephalon and the nerves 

 of the median region. Cut surfaces are striated. The external surface view of 

 the right side of the brain of head B is shown in perspective. The dotted line 

 represents the ventricles of the diencephalon and forebrain projected upon the 

 surface. Esophagus, trachea, tongues, and the conjoined periotic cartilages 

 are added in diagram to show their relative relationships to the nervous system. 



