226 



On the Occurrence of Heterotypical Mitoses in Cancer. 

 By E. F. Bashford, M.D., and J. A. Murbay, M.B., B.Sc. 



(Communicated by J. Kose Bradford, M.D., F.R.S. Eeceived November 2, — 

 Bead November 23, 1905.) 



[Plates 5 and 6.] 



The present paper refers to a communication* made to the Boyal Society 

 in January, 1904. In that paper and its expansion,! published later, we 

 emphasised the significance of the zoological distribution of cancer ; we 

 discussed the unique features of the processes responsible for the experi- 

 mental transmission of carcinoma from one animal to another and the 

 limitations to its successful attainment : we also published a series of figures 

 depicting the characters of the nuclei of cancer cells during division, in the 

 malignant new growths of fishes and mammals. "We shall give a different 

 explanation of the mitoses we figured in our earlier communications as 

 resembling the heterotypical mitoses of reproductive tissue. We have found 

 that those mitoses may be interpreted as somatic mitoses with longitudinally 

 split chromosomes. Their apparent heterotypical form is thus due to 

 variations in the development of the achromatic figure, the peculiar form of 

 the chromosomes and their mode of attachment to the spindle. 



Our figures of heterotypical mitoses in cancer confirmed the observations 

 of Farmer, Moore and Walker, communicated^ to the Boyal Society at the 

 preceding meeting, but we dissociated ourselves from their conclusions on the 

 diagnostic value and the significance of the phenomenon. The amount of 

 chromatin entering into the equatorial plate of the dividing cells of human 

 cancer had long been known to be subject to diminution (von Hansemann,§ 

 1893), but the presence of heterotypical mitoses appeared to throw a new 

 light on its occurrence and meaning. 



We have pointed out that the characteristic changes accompanying the 

 heterotypical mitosis in the reproductive tissues are absent from cancer cells 

 undergoing what we regarded as this form of division, and that the want of 

 •correspondence extends to the stages which precede and follow it.|| We have 



* 'Koy. Soc. Proc.,' vol. 73. 



t First Scientific Keport, Cancer Kesearch Fund. 



\ ' Koy. Soc. Proc.,' vol. 72. 



§ ' Studien fiber die Spezificitat, den Altruismus und die Anaplasie der Zellen,' Berlin, 

 1893, etc. 



|| Loc. cit., and 1 Lancet,' April 1, 1905. 



