66 STRUCTURE OF COLORED BLOOD-CORPUSCLES. 



irregular at one or more points. This occurs in either of two 

 ways, viz. : by indentation and by protrusion ; sometimes the 

 one, sometimes the other, first takes place 5 frequently both 

 appear in different corpuscles at about the same time; occa- 

 sionally both are met with in the same corpuscles ; in differ- 

 ent preparations either the one 

 or the other predominates. 



First. In from fifteen min- 

 utes to an hour a very slight 

 indentation may appear, and 

 b gradually deepen, so that the 

 corpuscle be nearly cleaved 

 through; then the clefts may 

 gradually become shallower, so 

 c that again a mere indentation 

 is seen j finally, even this may 

 disappear, and the corpuscle be 

 rounded again (see Fig. 21, a). 

 Division into two separating 

 halves I have never observed 

 under these circumstances, al- 

 though I have often watched 

 for it. The furrow of every 

 corpuscle that I have caught 

 nearly cleaved through, either 

 remained stationary, or usually 

 retrogressed to a greater or less 

 extent. The retrogression may 

 stop at any point, and the fur- 

 rowing again increase j and 

 this going and coming of a 

 cleft, though taking place 

 slowly, may continue for some time, and then stop at any stage 

 of indentation. Sometimes indentations appear at two or more 

 points of the same corpuscle, and in their progress give rise to a 

 great variety of angular, regular, and irregular "rosette," " scal- 

 loped," " crenated/' "thorn-apple/' and " stellate" forms (see Fig. 

 21, &, c, d). The sharp-pointed ends seen in the last figure of d 

 are the extremes met with, and exceptional ; usually the ends are 

 plump and rounded. These forms, as well as those of single 

 cleft, after changing backward and forward, either persist or 

 become finally rounded off to a greater or less degree ; in some 



FIG. 21. SHAPE-CHANGES OF COLORED 

 BLOOD - CORPUSCLES BY INDENTA- 

 TION. 



a, progressing and retrogressing furrowing ; 



b, indentations leading to irregular forms; 



c, indentation s leading to more or less regular 

 forms; d, instances of extreme and excep- 

 tional forms, especially the sharp-pointed stel- 

 lated figure; e, four phases of form-change, 

 observed in one corpuscle, with separation of a 

 constricted portion. 



