1905.] On the Cytology of Malignant Growths. 34 3 



are also paralleled by similar occurrences that may be seen in the cells of the 

 testis, and they are known to occur during the maiotic divisions of some plants 



It is thus evident that hyperchromatic nuclei, that is, nuclei containing an 

 excessive number of chromosomes, may be produced in at least two ways : 

 firstly, by the inclusion of leucocytes, and the incorporation of the chromo- 

 somes belonging to these bodies with those of the cancer cells when mitosis 

 sets in ; secondly, through the formation, whether by amitosis or mitosis, of 

 multinucleate syncytia, and by the subsequent confusion and mixing of the 

 chromosomes originally belonging to two or more of the nuclei when the 

 equatorial plate stage is reached. 



These aberrant modes of division are found to proceed concurrently with 

 the normal somatic mitoses that are going on in other cells in their immediate 

 vicinity. It is impossible to say definitely whether there may exist any sort 

 of alternation between the two types, though we are inclined to think that 

 such is not the case. It is, however, important to notice that all the mitoses 

 described above, whether they are normal in the number of chromosomes 

 or not, agree in conforming to the somatic type of division. That is to say, 

 no matter how many or how few the number of chromosomes involved may 

 be, the spireme eventually divides into a number of rod-like elements, each 

 of which splits longitudinally, and the daughter chromosomes resulting from 

 such fusion are severally distributed between the daughter nuclei finally 

 produced. In such typical cases this of course means that each of the two 

 daughter nuclei receives one longitudinal moiety of such original chromosome. 



15ut as we pass inwards from the growing edge of the tumour we encounter 

 cells in which the nuclei exhibit important deviations from the ordinary 

 somatic type of mitosis, and exhibit the characters otherwise met with during 

 the heterotype division (c/. figs. 6, 7, 8). In the early stage of the phase of 

 such nuclei the spireme exhibits that characteristic bunched appearance 

 recalling the well-known contraction figure that is normally to be seen at the 

 onset of the maiotic phase, that is in the prophase of the heterotype mitosis, 

 in animals and plants. In addition to this, we have been able to ascertain 

 that at about the same stage the spireme thread exhibits the longitudinal 

 fission (fig. 6) that is highly characteristic, though perhaps not exclusively 

 confined to the prophase of the heterotype division. The fission is especially 

 well seen in those cases in which a marked polarisation of the spireme is 

 apparent. But the most striking evidence of the validity of the comparison 

 that we drew in 1903 between these particular nuclei and those of the 

 reproductive cells during the maiotic phase of the animals and plants does not 

 depend solely on the similar mode of evolution of the chromosomes from the 

 resting nuclei in the " gametoid " cancerous and the true reproductive 

 vol. lxxvii. — b. 2 c 



