EXPLANATION OF THE PLATES. 



the order Composites ; the stellate form of the cor- 

 puscles is speedily followed by their considerable 

 enlargement, rupture, and disaggregation ; the cor- 

 puscles represented in the upper half of the circle 

 have been acted upon by water, in which they 

 quickly lose their radiate aspect, swell, increase to 

 two or three times their original dimensions, ex- 

 hibit their contained molecules more clearly, and 

 which may frequently be seen in a state of the 

 greatest activity ; finally, the corpuscles become de- 

 formed in shape and burst. It may here be 

 remarked, that the blood of most of the Invertebrata 

 is colourless, arising from the fact of their blood 

 containing but one form of corpuscle, the colourless 

 blood corpuscle. In the Annelida, indeed, the 

 blood is red ; the colouring matter, however, is not 

 contained in the corpuscle, but in the plasma. 



