90 STRUCTURE OF COLORED BLOOD-CORPUSCLES. 



them the projection and immediate withdrawal of minute, conical, thorn-like 

 processes, whenever one blood-corpuscle came into the vicinity of another, 

 without, however, actual contact. It seemed almost as if one corpuscle were 

 attracting or drawing out the thorn-like process from the surface of the other. 

 In other instances, however, I observed the shooting forth and quick with- 

 drawal of these processes from the margins of corpuscles not in close vicinity 

 to others. As these processes appeared at the marginal surfaces of the blood- 

 corpuscles, before the latter had come in contact with other of their fellows, 

 I naturally regarded the phenomenon as one of spontaneous motion, mani- 

 fested by the colored blood-corpuscle. But- as in most instances the phenom- 

 enon was observed in corpuscles passing near each other, I was inclined to 

 attribute it to a certain power of mutual attraction, residing under certain 

 conditions in the colored blood-corpuscles. Having taken the precaution of 

 slightly warming the glass slide before putting the blood, quickly taken 

 from the vessels of the skin of a vigorous young man, upon it, and the tem- 

 perature of the surrounding air being ninety-six degrees F., or even more, at the 

 time, I also considered a certain amount of heat, at least ninety-eight degrees 

 F., as essential to the manifestation of the phenomenon. This view, how- 

 ever, proved to be erroneous, as I shall show directly. Although I have wit- 

 nessed this phenomenon on blood-corpuscles when in a state of rest, it 

 nevertheless is more frequently observed on blood-corpuscles in motion, as 

 when they are carried along by a current arising in the specimen under the 

 covering-glass, and resembling in character the current in the capillary vessels. 

 With this view, the drop of blood should be thinly spread upon the glass slide, 

 and quickly covered with the thin plate of glass. While the blood-corpuscle 

 is projecting the thorn-like process, its body elongates, resembling a uni- 

 polar cell, but with the withdrawal of the process generally assumes its 

 original round form ; bipolar or lemon-shaped corpuscles are also very fre- 

 quently met with in specimens of human blood. The same process is also 

 observed when the margins of two corpuscles actually touch each other very 

 slightly, and then slowly separate again. While separating, the thorn-like 

 processes will be drawn out at the exact place of contact, and either remain 

 permanent or disappear again after the separation has taken place. 



" That the normal heat of the human blood is not essential to the manifesta- 

 tion of spontaneous motion in the colored corpuscles, I discovered during the 

 past winter, while repeating my examinations of the structure of these bodies. 

 I then witnessed the phenomenon above described, without having warmed the 

 glass slide and covering-glass, and at the temperature of a moderately warmed 

 room. However, I observed a colored corpuscle of a constricted form, similar 

 to a figure of eight, slowly expanding, and finally resuming its original round 

 form. 



"From this we may conclude that the colored blood-corpuscle of man pos- 

 sesses not only a certain inherent power of contracting its body, but also of 

 resuming its original form by a subsequent expansion, a characteristic 

 property of the living protoplasm enabling the colored corpuscle to manifest 

 spontaneous motions, though not to so great an extent as is seen in the color- 

 less."* 



In his "General Conclusions and Summary," Lankestert says that the 

 viscid mass constituting the red blood-corpuscles of the vertebrata " consists 



* Op. cit., pp. 113-115. t Op. cit., p. 386. 



