Literary Noticks. vii 



the restifornie toward the walls of the fourth ventricle. The cells of 

 this region were in part atrophied. 



A certain amount of atrophy appeared in the inner part of the crus 

 of the cerebellum, which did not however extend above one-third the 

 length of the anterior root of the eighth. Deiter's nidulus sustains no 

 relationship to the acusticus. 



The Development of the Sympathetic System. (') 



The cells of the ganglia of the sympathetic chain are shown by 

 Gaskell to be trophic simply. The gray rami communicantes spring 

 from the ganglia and are distributed as trophic fibres to the roots 

 of each spinal nerve and their meninges and the bodies of the vertebrje. 

 The white rami communicantes are only between the tenth and twenty- 

 fifth spinal nerves and in the rami of the second and third sacral nerves 

 (in the dog). 



In the anterior region the white rami pass from the spinal nerves to 

 the ganglia and there separate into two groups; one set forms vaso- 

 motor fibres which are distributed peripherally as gray fibres, the other set 

 does not join the ganglia, but forms vicero-inhibitory fibres in the abdo- 

 men. The white rami of the posterior region pass to the hypogastric 

 plexus without joining the ganglia and form nervi rriffcntes (vaso- 

 inhibitory) and perhaps viscero-inhibitory fibres. 



Patterson believes with Gaskell that the sympathetic is primarily 

 unsegmented. Two views prevail as to its origin. Onodi and Birdsell 

 consider it a distinct proliferation from the spinal ganglion, and Balfour 

 from the spinal nerve (in either case ectodermal). 



In mouse and rat embryos of about eight days the first indication of 

 the formation of the sympathetic cord has been found. The general 

 condition of development then corresponds to that of the chick at the 

 end of the third A&y. The spinal nerve has extended almost as far as 

 the somato-sphlanchnic angle, and to the cardinal vein in places where 

 the latter is present; and in some sections the superior primary division 

 is visible. A change is now apparent among the cells of the meso- 

 blast surrounding the aorta. In the interval between the latter and the 

 cardinal vein an irregular group of cells is seen on the ventral side 

 of the intercostal arteries. This mass is composed of cells which stain 

 more deeply; the nuclei are larger and they are more often multi- 

 nucleate than adjacent cells. 



.. The mass is comparatively large cephalad, and tapers off and be- 

 comes indistinct caudad. There is no connection, fibrous or cellular, 

 with the spinal nerves or ganglia. Longitudinal sections show that 

 this mass is a long rod or column on either side the median line, con- 

 sisting of fusiform cells with ovoid nuclei and thread-like processes. 



I A, M. Patterson. Development of the Sympathetic Sysitem in Mammals, 

 Philosoph. Trans, Roy. Soc, Lend., 1890, pp. 159-186, 9 plates. 



