OCTOBEE 30, 1914] 



SCIENCE 



647 



on the pipette, all tlie cells within a more or 

 less definite zone about the pipette instantly 

 crenate. If now the experimenter blows into 

 the pipette very slightly (the pipette, of 

 course, still being in the drop) the cells imme- 

 diately round up and remain perfectly normal. 

 This alternate crenating and uncrenating the 

 cells can be indulged in repeatedly. 



Examination of red-blood cells kept for 

 hours in a moist chamber gives evidence that 

 probably there are a number of more or less 

 definite types and stages of crenation. In 

 preparations of crenated erythrocytes a vary- 

 ing number (dependent somewhat upon the 

 age of the preparation) are seen to undergo an 

 internal change (as noted by Kite) which is 

 characterized by the formation of refraetile 

 granules and rods, of somewhat definite size, in 

 the cell substance. The exact relation of this 

 phase to crenation has not yet been determined. 

 The deposition of these rods and granules is 

 very possibly a coagulation phenomenon. 

 Cells that have undergone such a change are 

 apparently more stable and less easily brought 

 back to the normal than crenated but optically 

 homogeneous corpuscles. Such cells can be 

 sucked up into a pipette and expelled into the 

 same or different drop without undergoing 

 any apparent alteration in shape or size. Such 

 a cell can, however, be brought back to the 

 normal by raising a needle against the cell 

 body and immediately lowering it. The gran- 

 ules and rods instantly disappear and the cell 

 immediately assumes an apparently perma- 

 nent normal outline and appearance. 



All of the above experiments can he per- 

 formed equally well whether the hlood cells he 

 mounted in an isotonic, slightly hypotonic or 

 slightly hypertonic solution. Certain of the 

 experiments, especially, would seem to indicate 

 that the phenomenon is apparently outside the 

 sphere of any possible osmotic process, depend- 

 ent upon an alteration in a hypothetical semi- 

 permeable membrane around the red-blood cor- 

 puscle. Rather the experiments would lead 

 one to suspect that the shape a red-blood cell 

 assumes is an expression of surface tension 

 forces. The experiments also serve to empha- 

 size the extreme irritability of protoplasm. 



n. Flagellation 



In an article^ to be published shortly in the 

 Journal, of Infectious Diseases, Kite records 

 a series of dark-field observations on the struc- 

 tural modifications undergone by the blood 

 cells of various vertebrates when mounted in 

 liquid plasma containing Einger's fluid and 

 hirudin and examined in sealed preparations. 

 He records dark field observations of various 

 types of both motile and non-motile processes 

 which appear on the blood cells of vertebrates. 



After studying certain of these structural 

 changes in sealed preparations by means of 

 the dark field and special condensers it seemed 

 of interest to more carefully study red-blood 

 cells mounted in a Barbour moist chamber 

 freely open to the air, and to determine 

 whether these changes could be seen by ordi- 

 nary transmitted light and without the aid 

 of special condensers. For this purpose the 

 following experiments were undertaken. It 

 should be recorded here that, although one 

 type of process mentioned below is apparently 

 coarser and of a somewhat different nature 

 than any of the processes figured by Kite, yet 

 there is no reason to suppose that this type of 

 process is anything more than possibly an- 

 other phase in the transformations described 

 by him. As can be determined by reference 

 to Kite's paper, priority of certain of the fol- 

 lowing observations made under somewhat 

 different conditions belong to him. Control 

 observations with hirudinized preparations 

 have been made with the same results. The 

 method of preparing the microscopic mounts 

 is the same as described above under crenation. 

 Immediately upon making the preparation 

 a large proportion of the red-blood cells are 

 seen to possess very short non-motile spinous 

 processes which line the entire periphery of the 

 cell. "Within forty to fifty minutes after the 

 preparation is made the erythrocj^tes are seen 

 to possess long processes, some of which exhibit 

 a rapid whip-like motion, others a slow undu- 



2 ' ' Some Structural Modifications of the Blood 

 Cells of Vertebrates," G. L. Kite. Bead before 

 the Society for Experimental Biology and Medi- 

 cine, April 15, 1914. 



