258 THE DIVISION OF LEUCOCYTES 



these bodies are in reality the centrosomes of the 

 cells. 



If a leucocyte has two lobes to its nucleus it will 

 divide into two cells; if it has three lobes it will divide 

 into three cells, and so on. It will thus be seen that 

 when these cells proliferate each daughter cell will have 

 one centrosome until that centrosome itself divides and 

 assumes the appearance of being polylobed. Further, 

 a tissue made up of such daughter cells would be de- 

 scribed as consisting of "mononuclear cells." The 

 chromatin-staining lobes within the leucocytes are there- 

 fore not nuclei but centrosomes, and the so-called 

 Altmann's granules, which have been variously sur- 

 mised to be collections of food or secretion, are the 

 elements of the chromosomes themselves. 1 As in 

 lymphocytes so in leucocytes, the chromosomes are 

 outside the nucleus. Divisions have been induced in 

 hundreds of leucocytes, and the procedure is always 

 the same in all of them (figs. 79-86). 



Now, the increased quantity of the azur dye con- 

 tained in the jelly did not improve the mitosis induced 

 in the lymphocytes; in fact, it seemed too strong for 



1 Professor Sherrington has a specimen of an eosinophile leucocyte of a 

 cat in which the individual granules are elongated and almost rod-shaped. 

 We have also seen elongated granules in these cells in human blood. 



