occurring in the Liquor Sanguinis. 145 



are formed at the moment of the withdrawal of the blood, from cor- 

 puscles previously circulating free in it. 



To proceed now to the main subject of my communication. If 

 a drop of blood containing these masses is mixed on a slide with an 

 equal quantity of saline solution, i to f per cent., or, better still, 

 perfectly fresh serum, covered, sui-rounded with oil, and kept at a 

 temperature of about 37° C, a remarkable change begins in the 

 masses. If one of the latter is chosen for observation, and its out- 

 Hne carefully noted, it is seen, at first, that the edge presents a 

 tolerably uniform appearance, a few filaments of fibrin perhaps 

 adhering to it, or a few small corpuscles lying free in the vicinity. 

 These latter still exhibit apparent Brownian movements, frequently 

 turning half over, and showing their dark rod-like border (Fig. 5, 

 a, I). After a short time an alteration is noticed m the presence 

 of fine projections from the margins of the mass, which niay be 

 either perfectly straight, or each may present an oval swelling at 

 the free or attached end or else in the middle (Fig. 2, 1). It is 

 further seen that the edges of the mass are now less dense, more 

 loosely arranged, or, if small, it may have a radiant aspect. Some- 

 times, before any filaments are seen, a loosening takes place in the 

 periphery of the mass, and among these semi-free corpuscles the first 

 development occurs. The projecting filaments above-mentioned 

 soon begin a wavy motion, and finally break ofi" from the mass, 

 moving away free in the fluid. This process, at fii'st Hmited, soon 

 becomes more general ; the number of filaments which project 

 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 difiicult 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 development 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, Jc). The more 

 active ones wander towards the periphery, pass out of the field. 



