ACTION OF REAGENTS. 47 



and soon one or two white corpuscles begin to pro- 

 ject from the surface of the clot. These protrude 

 more and more, and others make their appearance, 

 and all begin to throw out numerous amreboid pro- 

 cesses, which are actively advanced and retracted, 

 and by aid of which the corpuscles free themselves 

 entirely from the shrinking clot, and eventually 

 become free in the surrounding serum (Fig. 12). 



Preparations 11, 12, 13, 14. Action of Re- 

 agentsWater, Acetic Acid, etc, upon the 

 Frog's blood-corpuscles. The action of reagents 

 upon the white blood-corpuscle of the frog is ex- 

 actly the same as upon the mammalian white cor- 

 puscle; upon the red corpuscle it is in the main 

 similar, but in some cases a little different, the diffe- 

 rences partly depending upon the presence of the 

 nucleus. Thus water causes both the substance of 

 the corpuscle and the nucleus to swell up and become 

 spheroidal, and extracts the colored part of the 

 corpuscles; dilute acetic acid brings the nucleus 

 strongly into view, and decolorizes the rest of the 

 corpuscle, which, however, usually retains its oval 

 shape ; tamric acid causes the colored part to be 

 exuded from the stroma, to which it generally re- 

 mains attached as an irregular curdled mass (some- 

 times the colored part is precipitated around the 

 nucleus, and then the two may be ejected from the 

 stroma together) ; chloroform vapor causes the red 

 corpuscles to become decolorized, and arrests the 

 movements of the white corpuscles; but these, if not 

 acted on for too long a time or by too strong a mix- 

 ture of chloroform and air, resume again on replac- 

 ing the vapor by pure air. All these reagents are 

 applied in precisely the same manner as with the 

 mammalian blood, to the description of which the 

 reader is referred. 



The observations may be made with as great or 

 with greater advantage upon the blood-corpuscles of 

 the newt, which are larger than those of the frog. 

 The blood should be obtained directly from the 



