EXPLANATION OF THE PLATES. 



PLATE II. 



THE BLOOD OF THE FROG. 



Fig. 1. The blood corpuscle of the frog, both red and white, 

 with the nucleus of the former seen indistinctly. 



2. The same, with the nucleus distinctly visible, the 



difference arising from the greater length of time 

 during which the latter has been removed from the 

 system. 



3. The same, in water, showing the change of form 



which the red blood corpuscle, as well as its con- 

 tained nucleus, undergoes in that fluid, and also the 

 enlargement of the white corpuscles. 



4. The same, showing the effect of the prolonged action 



of water on the red corpuscles ; the nuclei are now 

 not merely circular, but most of them have become 

 eccentric, and certain of them have escaped alto- 

 gether from the membranous capsular portion of 

 the corpuscles, which and the nuclei are seen lying 

 side by side as distinct structures. 



5. The nuclei, separated from the capsule by the action 



of acetic acid. 



6. Shows the extraordinary deformity and elongation of 



which the red blood corpuscles are susceptible 

 when subject to any extending force, or even to 

 lateral pressure. In the figure the extension has 

 been exerted on the corpuscles by means of the 

 filaments which fibrin in coagulating runs into, and 

 a portion of one of which may be seen uniting the 

 corpuscles. 



