102 , 'v/:j; : . MYSIOLOGY CHAP. 



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 

 35-37 C., 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 e fleets upon erythrocytes of discharge from a Leyden jar. (Rollett.) o, 

 normal erythrocyte ; 7>, rosette form ; <;, mulberry form ; d, prickly form ; e, .rounded and 

 swollen erythrocyte ; /, 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 hydrochloride 

 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- 



a $ ^ d 6 s i um ferrocyanide must be considered as 



ft ft A O O active movements of the protoplasm. Ery- 



throcytes have a fairly tenacious vitality, 



LV When taken out of the blood-vessels and 



-jffi* / (~*$ reinjected, they survive after as much as 



* -^ V-x^ 4_5 days, but only provided they are kept 



FIG. 29. , Successive effects upon jf l- lp < 3 f-^ r l f n CO p fl-mir ^i'o onrl 

 erythrocytes of water (Schafer); m 1C6 - if nea tea 10 OZ b., lllQJ QIC and 



c' action oftenn^adli f ^^ ' ^ rea k up when reintroduced into the 

 circulation. If 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.mm.) 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 Thonia-Zeiss. 



Haemacytometer of Thoma-Zeiss. In ordel- 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 



