DR. MARTIN BARRY ON FIBRE. Ill 



shown that the same structure is rendered visible by other reagents; such as the 

 compounds of silver, and of chrome. It is singular that the objection to the use of 

 chemical reagents should have been mooted by parties in the habit of employing ma- 

 ceration, a process of course highly destructive when prolonged for many days. 



96. But the filament may be discerned without any addition whatever, if the coa- 

 gulation has begun, provided its appearance has become familiar to the eye. In the 

 blood of the Newt when so viewed (i. e. without any addition) the discs containing 

 filaments often resemble flask-like vesicles (fig. 149). The membrane of most of the 

 little flasks exhibits folds or creases (ft), converging towards the extremity of the 

 neck. If this extremity is very carefully examined, it is often found that there is a 

 small body protruding (y) : this is no other than the extremity of the filament in 

 question. It is now sometimes possible to discern that the folds just mentioned, 

 mark the situation of the filament within the flask (S). Occasionally a portion of the 

 filament protrudes, sufficient to admit of its remarkable structure (par. 6) being seen. 

 Sometimes the neck of the flask is bent (J3) ; so that, with the filament, there is pro- 

 duced the appearance of a comma. Still, as before said, for a complete examination 

 of coagulating blood, it is advisable to remove a portion of the red colouring matter 

 by some chemical reagent-^-. 



9". There is considerable variety in the appearance of the red portion of the clot. 

 In that of various Mammals, I have seen the following objects: namely, 1. parent 

 cells;}: (fig. 148 a) filled with young corpuscles, resembling Ammonites; 2. groups of 

 young corpuscles (|3), each of which was unwinding into a filament, and comparable 

 to a Turrilite in form ; 3. similar objects of larger size (y), also in groups, as if dis- 

 charged from parent cells ; 4. spiral fasciculi of filaments (5), such as would be pro- 

 duced by the continued elongation and self-division which is represented as incipient 

 in the corpuscles at y. In other instances, the fasciculus of filaments has seemed to 

 arise directly out of a parent cell; by the simultaneous metamorphosis, into fila- 

 ments, of all the contained blood-discs. 



98. The undulations to be observed in the filaments of "cellular" tissue, seem re- 



t When first endeavouring to find the filament in question, the observer should use the clot in blood of the 

 Prog or Newt, three or four hours drawn. Having placed upon a strip of glass a drop of the solution of nitrate 

 of silver, introduce into it a portion of this clot ; and with needles break the same into very minute parts ; cover 

 these with a piece of thinner glass ; press the two glasses firmly together ; and view with a power of 400 or 

 500 diameters. To find the little flasks above described, proceed in the same manner, and use the same clot, 

 but without adding any chemical reagent. Blood (of one of the same animals) should then be examined, first 

 with, and then without chemical reagents, just before its coagulation : and subsequently at various periods 

 during the formation of the clot. I generally employ the Newt (Lissotriton punctatus of BELL) : and obtain 

 the blood by touching a strip of glass with the part from which the head has been removed ; immediately adding 

 a drop of the solution of nitrate of silver, and then a piece of thinner glass. This is done at the end of half a 

 minute, and repeated in one minute, &c. for two or three minutes. The first perceptible changes in coagula- 

 tion may be thus observed. 



J These parent cells, usually elliptical, measured in length from ^'" to j'jy'" (Paris line), and were met 

 with even of a larger size. Their colour blood-red. 



