Abstract from notes on the minute structure of the spinal cord / by John B. Trask.

  • John Boardman Trask
Date:
1860
Catalogue details

Licence: Public Domain Mark

Credit: Abstract from notes on the minute structure of the spinal cord / by John B. Trask. Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

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    [13] Experimental Phjslology, (Comte Rendne, tome 48, March, 1859, page 502,) M. Jacubowitsch states that these cells are very small, les plus petites. This does not accord with my observations in regard to them, for in the cer- vical region I have met with them equal in length, but not so broad as the caudate cells of the other cornua, and as to their number in this region of the cord, they come fully up to the latter. I am unable to account for this discrepancy in any other manner than by supposing that this observer founc.ed his remarks on views of the transverse diameter of these cells, at right angles to their poles ; that view would, in- deed, present them plus petites. As we are left in the dark entirely as to where he foimd them so small, it becomes very difficult to verify his state- ment in this particular. It is only in vertical sections of the cord that we shall find ourselves able to bring out these corpuscles with anything like distinctness. When thus found they are regular in form, having a centric nucleus and nucleolus, but they do not in section, and when in situ, present those bifid prolongations which are found attached to them in the improved and borrowed plates. In extremely thin sections, (one seven-hundredth of an inch,) these cells are examined to advantage in their natural positions; we can now discover a colorless fibre projecting from either pole of the cellule, extending in a slightly tortuous line, but vertical to the major axis of the corpuscle. I find it not very difficult to discover bifid cauda attached to the fibrillated pro- longations of the cells, when by the use of needles, the compressorium, and other mechanical appHances, and hard work combined, we are thus enabled finally to teaze, squeeze, and grind one of these fibres, until by the force thus used these delicate elements are made to assume phases which it seems to me are entirely foreign to their character. Such a process for delineating these delicate tissues it appears to me would be analagous to an artist painting infantile beauty, while the innocent was writhing under exquisite torture. As Dr. Funke has remarked, and most justly, too, of the delineations in another department of microscopic research, they have taken on forms of outline so foreign that it would be difficult to imagine what the figures were intended to represent. The relative position which the vertical axis of these cellules maintain to the surrounding parts is of some importance, both as regards their anatomi- cal position, and also for facilitating our examinations, for if the cord is ex- amined for them through its horizontal plane, those corpuscles will seldom, if ever, be met with in place. So far as I have examined the cord, the fusiform cells have been found in the post'^rior cornua exclusively, and in no instance have any been seen by me in the posterior columns of the organ. I have not been more successful in findins them lateral to these cornua, than in the examinations conducted on the posterior columns. The relations to the planal position of these corpuscles I find to be as follows : their planes are vertical to those of the caudate cells of the anterior cornua, and they thus become parallel to the major axis ot the cord, and also with the quadrate corpuscles before spoken of in the anterior columns*
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