1874.] in the Liquor Sanguinis. 395 



fibrin perhaps adhering to it, or a few small corpuscles lying free in 

 the vicinity. These latter soon exhibit apparent Brownian movements, 

 frequently turning half over, and showing their dark rod-like border 

 (fig. 5, a, b). After a short time an alteration is noticed in the presence 

 of fine projections from the margins of the mass, which may be either 

 perfectly straight, or each may present an oval swelling at the free or 

 attached end or else in the middle (fig. 2, b). It is further seen that 

 the edges of the mass are now less dense, more loosely arranged, or, if 

 small, it may have a radiated aspect. Sometimes, before any filaments 

 are seen, a loosening takes place in the periphery of the mass, and among 

 these semifree corpuscles the first development occurs. The projecting 

 filaments above mentioned soon begin a wavy motion, and finally break 

 off from the mass, moving away free in the fluid. This process, at first 

 limited, soon becomes more general ; the number of filaments which pro- 

 ject from the mass increases, and they may be seen not only at the lateral 

 borders, but also, by altering the focus, on the surface of the mass, as 

 dark, sharply defined objects. The detachment of the filaments proceeds 

 rapidly ; and in a short time the whole area for some distance from, the 

 margins is alive with moving forms (fig. 2, c, and fig. 3), which spread 

 themselves more and more peripherally as the development continues in 

 the centre. In addition to the various filaments, swarming granules are 

 present in abundance, and give to the circumference a cloudy aspect, 

 making it difficult to define the individual forms. The mass has now 

 become perceptibly smaller, more granular, its borders indistinct and 

 merged in the swarming cloud about them ; but corpuscles are still to be 

 seen in it, as well as free in the field. A variable time is taken to arrive 

 at this stage ; usually, however, it takes place within an hour and a half, 

 or even much less. The variety of the forms increases as the develop- 

 ment goes on ; and whereas, at first, spermatozoon-like or spindle-shaped 

 corpuscles were almost exclusively to be seen, later more irregular forms 

 appear, possessing two, three, or even more tail-like processes of extreme 

 delicacy (fig. 5, &). The more active ones wander towards the periphery, 

 pass out of the field, and become lost among the blood-corpuscles. The 

 process reaches its height within 2| hours, and from this time begins 

 almost imperceptibly to decline ; the area about the mass is less densely 

 occupied by the moving forms, and by degrees becomes clearer, till at 

 last, after six or seven hours (often less), scarcely an element is to be seen 

 in the field, and a granular body, in which a few corpuscles yet exist, is 

 all that remains of the mass. The above represents a typical develop- 

 ment from a large mass in serum, such as that seen in fig. 3*. 



We have next to study more in detail the process of development 

 and the resulting forms. Commonly, the first appearance of activity is 



* The mass from which this sketch was taken was seen in full development by several 

 of the foreign visitors to the British Medical Association last year. 



