AMCEBOID MOVEMENTS OF THE COLOURLESS CORPUSCLES. 



*5 



Human leucocytes showing amoeboid 

 movements. 



The amoeboid movements of the white corpuscles (so called because they 

 resemble the movements of amoeba) consist in an alternate contraction and relaxation 

 of the protoplasm surrounding the nucleus. Processes are given off from the 

 surface, and are retracted again. There is an internal current in the protoplasm, 

 and the nucleus has also been observed to change its form [and exhibit contractions 

 without the corpuscle dividing. The ^ 



karyokinetic aster, and convolution of the 

 intranuclear plexus have been seen]. Two 

 series of phenomena result from these 

 movements: (1) The "wandering" or 

 locomotion of the corpuscles due to the 

 extension and retraction of their processes ; 

 (2) the absorption of small particles into 

 their interior (fat, pigment, foreign bodies). 

 The particles adhere to the sticky exter- 

 nal surface, are carried into the interior 

 by the internal currents, and may eventu 

 ally be excreted, just as particles are taken 

 up by amoeba and the effete particles 

 excreted. [Max Schultze observed that 

 coloured particles were readily taken up by 

 these corpuscles. Conditions for move- 

 ment. In order that the amoeboid movements of the leucocytes may take place, 

 it is necessary that there be (1) a certain temperature and normal atmospheric 

 pressure ; (2) the surrounding medium, within certain limits, must be " indifferent,'" 

 and contain a sufficient amount of water and oxygen ; (3) there must be a basis or 

 support to move on.] 



Struggle between Microbes and the Organism. Metschnikoff emphasises the activity of the 

 leucocytes in retrogressive processes, whereby the parts to be removed are taken up by them in 

 fine granules, and, as it were, are "eaten." Hence, he calls such cells "phagocytes." They 

 may be found in the atrophied tails of batrachians, the cells containing in their interior whole 

 pieces of nerve-fibre and primitive muscular bundles. Schizomyeetes which have found their 

 way into the blood ( 183) have been found to be partly taken up by the colourless corpuscles. 

 [The spores of a kind of yeast are similarly attacked in the transparent tissues of the water- 

 flea by the leucocytes, and the connective-tissue cells also destroy microbes.] 



Effect of Reagents. On a hot stage (35-40 C.) the colourless corpuscles of 

 warm-blooded animals retain their movements for a long time ; at 40 C. for two 

 to three hours; at 50 C. the proteids are coagulated and cause "heat rigor'' 

 and death, [when their movements no longer recur on lowering the temperature]. 

 In cold-blooded animals (frogs), colourless corpuscles may be seen to crawl out of 

 small coagula, in a moist chamber, and move about in the serum. [Draw a drop 

 of newt's blood into a capillary tube, seal up the ends of the latter and allow the 

 blood to coagulate. After a time, examine the tube in clove oil, when some of the 

 colourless corpuscles will be found to have made their way out of the clot.] 

 Induction shocks cause them to withdraw their processes and become spherical, 

 and, if the shocks be not too strong, their movements recommence. Strong and 

 continued shocks kill them, causing them to swell up, and completely disintegrating 

 them. 



Diapedesis. These amoeboid movements are of special interest on account of the 

 " wandering out " (diapedesis) of colourless blood-corpuscles through the walls of 

 the blood-vessels ( 95). 



[Effect of Drugs. Acids and alkalies, if very dilute, at first increase, but afterwards arrest 

 their movements. Sodic chloride in a 1 per cent, solution at first accelerates their movements, 

 but afterwards produces a tetanic contraction, and, it may be, expulsion of any food particles 

 they contain. The Cinchona alkaloids quinine, quinidine, cinchonidine (1 : *1500) quickly 



