102 PHYSIOLOGY CUM-. 



ferrocyanide or a highly dilute solution of potassium sulpho- 

 cyanide had been added in the proportion of about 1 per 1000, 

 and then examined under the microscope at a temperature of 

 .">r>-37 0., the erythrocytes of man and other mammalia (not 

 of birds and batracians) put out delicate prolongations like cilia, 

 the rapid vibratory movements of which enable the corpuscles 

 to oscillate, rotate, or move forward. These cilia-like pseudopodia 



FIG. 28. Successive effects upon erythrocytes of discharge from a Leyden jar. (Rollett.) a, 

 normal erythvoeyte ; '/, rosette form; <, mulberry form; <l, prickly form; e, .rounded .and 

 swollen rrythrooyte ; /, ghost. 



rise from the smooth surface of the erythrocytes, and vary in 

 length and number. Their movements of expansion and retraction 

 are slow and limited. If a drop of solution of cocaine by drochloride 

 is added to the preparation, the erythrocytes resume their former 

 shape in a few moments. If washed free of the cocaine, and 

 treated afresh with the ferrocyanide, they may resume their 

 ciliated aspect. 



Since, according to the researches of Albertoni, cocaine paralyses 

 protoplasm, it follows that the changes of form exhibited by the 



erythrocytes under the influence of potas- 

 5 c & sium ferrocyauide must be considered as 



P^ Q O O active movements of the protoplasm. Kv\ - 



throcytes have a fairly tenacious vitality. 

 When taken out of the blood-vessels and 

 a C*^& reinjected, they survive after as much as 

 ^-^ 4-5 days, but only provided they are kept 



FIG. 2<t. a, Successive effects upon Tf V, pa f pr l f n FJO P tbav rlio aurl 

 erythrocytes of water (Sch.ifer); m 1 l ^^ ^-> tnev CUe ano - 



b, action of a solution of salt ; break up when reintroduced into the 



e, action of tannic acid. . i . T f> c -\ i 



circulation. It transfused into animals of 



a different kind they do not survive, but degenerate and disin- 

 tegrate more or less rapidly, owing to the heterogeneous plasma 

 with which they are brought in contact. 



The direct enumeration of the corpuscles contained in a given 

 quantity of blood (1 c.nim.) was correctly performed for the first 

 time by Vierordt and Welcker (1854), the results they obtained 

 having been confirmed by more recent observers. The method 

 and apparatus have been perfected, and are now practical and 

 easily applicable for clinical purposes. We must here confine 

 ourselves to naming those of Malassez, Hay em, and Thoma-Zeiss. 



Haemacytometer of Thoma-Zeiss. In order to count blood-corpuscles with 

 the Thoma-Zeiss apparatus, the point of the capillary glass pipette (Fig. 30, 

 I) is dipped into the drop of blood to be examined, which is obtained by 



