390 THE BLOOD, BY ALEXANDER ROLLETT. 



blood with the glass cover may be easily displaced, the sparks 

 then passing directly from one electrode to another. Moreover, 

 the surface of the flask must not materially exceed the above, 

 or the discharging shock will occasion electrolysis (scarcely per- 

 ceptible in the above-mentioned arrangement) to occur to an 

 extent which may seriously interfere with the result. When 

 these conditions are preserved, and the discharges are made to 

 succeed each other at intervals of from three to five minutes, 

 the following consecutive changes may be observed in the 

 blood corpuscles : 



The circular disk-like corpuscles (fig. 70, a) in the first in- 

 stance present one or two projections at their borders, and these 

 gradually increase in number to three, five, or more. 



Fig. 70. 



I have named this form the rosette form (fig. 70, 6) ; it passes 

 gradually into the mulberry form (fig. 70, c), which can always 

 be produced at will by the discharge. To this succeeds a stage 

 in which the processes become pointed, so that the corpuscles 

 assume more the form of a paradise apple (horse chestnut) (fig. 

 70, d). Lastly, all the spikes are withdrawn, and a coloured cor- 

 puscle results (fig. 70, 6),which then loses its colour, and a smooth 

 colourless body is left (fig. 70, /), that long remains in the fluid 

 in an unaltered condition. 



In the case of the frog the blood corpuscles first assume a 

 spotted appearance. Local thickenings then occur in the direc- 

 tion of the shortest diameter, which for the most part proceed 

 radially from the nucleus (fig. 71, a and 6). This, however, is 

 not always the case ; for it sometimes happens that the thick- 

 enings are nearly perpendicular to the longest diameter of the 

 corpuscle, and cross it in the form of transverse bands. The lat- 

 ter is of most frequent occurrence in the blood of tritons. Upon 

 this stage, which is obviously analogous to the first (fig 70, 6) 

 and to the second (fig. 70, c) stage in the blood corpuscles of 



