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IX. Researches on the Intimate Structure of the Brain. — Second Series. 
By J. Lockhart Clarke, F.R.S., &c. 
Received May 1, — Read May 23, 1867. 
CHAPTER I. 
(1) Before I begin to describe the parts which form the subject of this communica- 
tion, and to show how some of them are merely modified portions or developments of 
others that belong to the medulla oblongata , it will be advisable to recur to those 
morphological changes in the medulla, which I formerly pointed out as themselves 
arising from modifications of the spinal cord. And while in unravelling structures so 
extremely complex, such a course seems almost necessary to facilitate their compre- 
hension, and convey to the reader a just notion of their morphological changes, in rela- 
tion on the one hand, to the remaining parts of the encephalon, and on the other 
hand, to the spinal cord, it will afford me an opportunity of adding to this recapitula- 
tion some new facts that have been elicited by subsequent observation and a more ex- 
tended experience. 
It is gratifying to know that many of the results of my previous researches have been 
found to throw considerable light on certain diseases of the nervous system, especially 
on some forms of paralysis ; and my own pathological investigations, as well as a close 
study of nervous disorders, have not only enabled me to shape my present researches as 
much as possible in accordance with the requirements of the pathologist, but, by point- 
ing to the probability of certain anatomical connexions suggested by morbid symptoms, 
they have sometimes been the means of directing the course of my dissections in a very 
peculiar way*. 
Some of the results comprised in this communication were obtained by adopting the 
method of dissection which I so strongly recommended in my former Memoir on the 
Medulla Oblongata. This plan consists in first making a number of delicate and careful 
dissections in the course of the fibres of the medulla, after it has been well hardened in 
strong spirit of wine, and then examining microscopically thin sections, made in dif- 
ferent directions, and rendered transparent by the method which is known as my own. 
By this means we may often succeed in unravelling structures which are so complex 
that the investigation at first sight appears to be almost hopeless. Before the first dis- 
* Dr. Hugh lings Jackson (Physician to the Hospital for Paralysis and to the London Hospital) was the 
first to apply with great ability and industry the recent advances made in the minute anatomy of the nervous 
centres to the explanation of certain forms of paralysis. See especially ‘ The London Hospital Reports,’ 
vols. i. and ii. ; ‘ Ophthalmic Hospital Reports,’ vol. v., &c. 
MDCCCLXVIII. 2 P 
