78 HAND-BOOK OF PHYSIOLOGY. 



A somewhat similar effect is produced on the human red blood -cell. 

 (Koberts.) Magenta, when applied to the red blood-cells of the [frog, 

 produces a similar little knob or knobs, at the same time staining the 

 nucleus and causing the discharge of the haemoglobin. (Roberts.) The 

 first effect of the magenta is to cause the discharge of the haemoglobin,, 

 then the nucleus becomes suddenly stained, and lastly a finely granular 

 matter issues through the wall of the corpuscle, becoming stained by the 

 magenta, and a macula is formed at the point of escape. A similar 

 macula is produced in the human red blood-cell. 



Boracic acid. A 2 per cent, solution applied to nucleated red blood- 

 cells (frog) will cause the concentration of all the coloring matter in the 

 nucleus; the colored body thus formed gradually quits its central position, 

 and comes to be partly, sometimes entirely, protruded from the surface 

 of the now colorless cell (Fig. 73). The result of this experiment led 

 Briicke to distinguish the colored contents of the cell (zooid) from its 

 colorless stroma (oacoid). When applied to the non-nucleated mammalian 

 corpuscle its effect merely resembles that of other dilute acids. 



Gases Carbonic acid. If the red blood-cells of a frog be first exposed 



Vf* 



& 



FIG. 73. FIG. 74. FIG. 75. 



to the action of water-vapor (which renders their outer pellicle more 

 readily permeable to gases), and then acted on by carbonic acid, the 

 nuclei immediately become clearly defined and strongly granulated; when 

 air or oxygen is admitted the original appearance is at once restored. 

 The upper and lower cell in Fig. 74 show the effect of carbonic acid; the 

 middle one the effect of the re-admission of air. These effects can be 

 reproduced five or six times in succession. If, however, the action of the 

 carbonic acid be much prolonged, the granulation of the nucleus becomes 

 permanent; it appears to depend on a coagulation of the paraglobulin. 

 (Strieker.) 



Ammonia. Its effects seem to vary according to the degree of con- 

 centration. Sometimes the outline of the corpuscles becomes distinctly 

 crenated; at other times the effect resembles that of boracic acid, while 

 in other cases the edges of the corpuscles begin to break up. (Lankester.) 



Heat. The effect of heat up to 120 140 F. (50 60 C.) is to 

 cause the formation of a number of bud-like processes (Fig. 75). 



Electricity causes the red blood-corpuscles to become crenated, and 

 at length mulberry-like. Finally they recover their round form and 

 become quite pale. 



