348 THE AMERICAN MONTHLY [Nov. 



single cell, and along with its independent value, «teps 

 undeniably to the front. Until now this view of the 

 cellular pathology has held its own against the dangerous 

 attack of Grawitz, who finds in already formed inter- 

 cellular substances under certain conditions the matrix of 

 a new cell growth. If, then, the positive karyokinetic 

 pictures are at the present time the firmest support of 

 the cellular pathology and the most obvious proof of an 

 independent cell action, likewise it is certainly a question 

 of the utmost importance whether we can immediately 

 detect with the microscope in how far the existing cells 

 of a certain tissue are capable of propagation. Of course, 

 we do not always surprise them in this act, and we are 

 often in the position to accept upon mere analogies a cell 

 formation by division, where the unkindness of the speci- 

 men for examination will not permit us to give positive 

 proof by the direct presence of a karyokinetic picture. 

 In this condition it is certainly of special value for the 

 specimen of normal or pathological anatomy if we 

 possess a method which will inform us as regards 

 the faculty of proliferation of the resting nuclei (the 

 connective tissue cells, epithelial cells). 



For some time past I have noticed a certain kind of 

 nucleus in pathological structures, especially in chronic 

 inflammation and new formations, which manifests itself 

 by its especial size and stronger staining qualities. In 

 some new formations — for instance, in leproma — these 

 acquire a noticeable size ; they are mostly of oval form, 

 show a f]ne chromatine thread-work which is not 

 essentially of greater staining power than the nuclear 

 juice — and are surrounded by some protoplasm. As they 

 take, with the use of certain stains of which I shall 

 speak, also a meta-chromatic color in contradistinction to 

 the ordinary nuclei, I subjected them to a more careful 

 examination as regards their ability of retaining stains, 



