28 BLOOD CORPUSCLES. 



the nucleus is pale. It contains numerous distinct granules, 

 which show active Brownian movement. It not unfrequently 

 happens, that a much-swollen spheroidal corpuscle, after re- 

 maining a length of time in its place without change, is torn 

 away from its attachment to the glass by the current, in which 

 case it may either divide into two masses, one of which con- 

 tinues adherent, while the other floats away, or it may float 

 away en masse, leaving behind it a long filament, by which it 

 is still connected with its original point of adhesion. By re- 

 newing the irrigation, the filament will probably be severed. 

 It is thus proved that the colorless corpuscle consists of a soft 

 viscous substance. The final result of the action of water on 

 the colorless corpuscles is alwa} T s disintegration; the mass 

 suddenly disperses into the surrounding medium, all that re- 

 mains of the previously so active entity is a collapsed, form- 

 less clump, in which one or two motionless granules may be 

 seen. 



In the colored blood disks, the first change is that their 

 surfaces become smooth, their contour becomes circular, the 

 nucleus rounder and brighter than before, the corpuscle paler 

 and paler, until its outline is scarcely distinguishable. Two 

 phenomena are worth noticing before we proceed further. 

 The first is, that, at the commencement of irrigation with dis- 

 tilled water, it occasionally happens that, immediately their 

 surfaces have become smooth, the corpuscles suddenly assume 

 a rounder and smaller appearance, and are more intensely 

 colored : quickly returning, however, to the elliptical form, 

 and losing their color as before. The second will be explained 

 later: a colored corpuscle appears to have separated into two 

 parts, a pale elliptical disk and a yellow mass, occupying a 

 central, or, more frequently, an eccentric position within it, 

 from which colored processes often stretch out like rays 

 toward the periphery. 



Strieker's Method. There is another method of studj'ing 

 the action of water on the colored corpuscles. For this pur- 

 pose we require the warm stage (Fig. 2). A drop of water is 

 placed on the floor of the chamber, and on the middle of the 

 surface of the cover-glass a drop of blood, either pure or di- 

 luted with salt solution. The cover-glass is then inverted 

 over the chamber, the edges of which have been previously 

 oiled, or surrounded with a ring of putty, so that it is air- 

 tight. By warming the copper wire the water is made to 

 evaporate from the floor of the chamber, and becomes con- 

 densed on the under surface of the cover-glass. In this way 

 we are enabled to study the gradual action of water on the 

 corpuscles very advantageously. 



Action of Salt Solution on the Blood Corpuscles of 

 Mammalia. In mammalian blood which has been diluted 



