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SUMMARY OF CURRENT RESEARCHES RELATING TO 
The formation of the ganglia on the main cord of the sympathetic is 
a subsequent event, and is subordinate to the connection of the splanchnic 
branches of the spinal nerves with the cord. The causes leading to the 
formation of the ganglia are : mainly, the junction of the splanchnic 
branches, and the accession of a large number of nerve-branches at the 
point of entrance ; the consequent persistence of the cells of the cord, 
which are joined by these nerves, as ganglion cells ; and, to a less extent, 
the anatomical relations of the cord to the bony segments, &c., over 
which it passes ; for these, in their growth, cause indentation of the 
cord at certain points. 
Details are given as to the cephalic and caudal terminations and the 
peripheral branches. 
From the morphological point of view, the most important of Prof. 
Patterson’s conclusions are (1) that the sympathetic system is not a 
specialized portion of the central nervous system but has an independent 
origin, and is only secondarily connected with the cerebro-spinal system, 
and (2) that it is developed from the mesoblast. 
It is very possible that under the term “ sympathetic nervous system ” 
there have been included two structures, entirely independent in nature, 
origin and function, one the sympathetic and the other the nervous system 
proper. 
Degeneration of the Follicle in the Mammalian Ovary.* — Dr. T. 
Schottlaender finds that the degeneration of the follicle is an almost 
uniform process in the ovaries of the guinea-pig, rat, mouse, and dog. In 
primordial follicles, no more than a fatty degeneration of the epithelium 
was observed ; but degeneration may befall all other follicles, especially 
those which are half ripe. The process usually begins with the destruc- 
tion of the ovum ; then the epithelium degenerates ; before the latter 
disappears there is remarkable proliferation in the theca. 
The zona of the ovum seems to become swollen and hyaline ; the 
yolk undergoes fatty degeneration ; the germinal vesicle is subjected to 
chromatolysis. Hints of irregular processes of nuclear division are 
observed, but Schottlaender saw only two figures which could be regarded 
as “ directive.” The granulosa cells migrate into the yolk, which de- 
generates completely and is absorbed. The epithelium degenerates in 
various ways : — the chromatin of its nuclei is destroyed and the cells 
become smaller and paler, or the cells undergo fatty degeneration with- 
out chromatolysis, or both processes are combined. Before ovum and 
epithelium are finally dissolved, the theca proliferates. A layer of 
connective tissue with blood-vessels and with fat sinks into the follicular 
space, but this layer varies considerably according to the age of the 
follicle and in different animals. What relation this connective-tissue 
body, which marks the disappearance of a follicle, may bear to the 
appearance of its successor, is still unknown. 
B. Histology. 
Attraction-Spheres and Central Bodies in Tissue and Migratory 
Cells. t — Prof. W. Flemming, referring to the few observations that have 
* Arch. f. Mikr. Anat., xxxvii. (1891) pp. 192-238 (2 pis.), 
t Anat. Anzeig., vi. (1891) pp. 78-81 (5 figs.). 
