PREFACE 9 



chromosomes of lymphocytes are formed from the 

 Altmann's granules in the cytoplasm. This was 

 specially the case in one of the cities in the United 

 States, where I happened to obtain some good 

 specimens. "When first the figures were seen, 

 the observers seemed unanimous about the cell- 

 division ; but after I had again shown them a 

 resting cell for comparison and explained the 

 figures, minutely pointing out the revolutionary 

 fact about the chromosomes, our critics were not 

 quite so unanimous. This is to be expected, and 

 until the fallacies of " fixed " specimens and of 

 the examination of unstained living cells are 

 appreciated, we cannot hope to have our work 

 established. Without exception, however, all 

 observers seemed to be agreed that a new field 

 for research has been opened and that the figures 

 in the cells are unique. 



Several reviewers have suggested that the 

 division-figures are "artefacts" or are results of 

 degeneration. Pathologists seem to be prone to 

 label new phenomena with these expressions, but 

 personally I think that no one can criticise 

 researches of this nature without seeing the experi- 

 ments themselves. Our answer to these allegations 

 is that the cells always undergo a definite process 

 before they divide ; a series of figures is formed 

 identical in every case ; the chromatin is collected 

 together, splits usually into a definite number of 

 rods or pear-shaped bodies, some of which travel 

 to one pole of the cell and some to the other ; and, 

 lastly, where there was one cell there are now two. 

 We shall be most happy, however, to show the, 

 experiments to any one interested, 



