CYTOLOGY OF CANCER 161 



time on the part of the reader than could be demanded in a work 

 of this nature. Some reference must, however, be made to the 

 work which is being done in this direction. Summed up briefly, 

 it may be said that the amount of information concerning the 

 behaviour of cell constituents during the cell cycle in a very large 

 number of pathological conditions is enormous, but that so far no 

 outstanding co-ordinating facts can be produced. 



A very comprehensive account of the cytology of cancer will 

 be found in a paper by Ludford (80). A few examples will show 

 how difficult it is to draw any general conclusions whatever. As 

 regards the behaviour of the chromosomes during mitosis, all 

 types of aberrations may be found from the normal behaviour 

 {e.g., squamous-cell sarcoma of the mouse) to pluripolar (car- 

 cinoma) and abortive (epithelioma) mitoses. Fig. 13, in the paper 

 referred to above, summarises the many different phenomena met 

 with. 



Turning to the protoplasmic inclusions, we find the same 

 divergence in the phenomena present. Considerable hypertrophy 

 of the Golgi apparatus and mitochondria may occur as in 

 hypertrophied cancer cells in the fibro-sarcoma of the rat. The 

 extent to which this may be found varies even between different 

 specimens of experimentally induced tar cancers on the same 

 animal. Similarly, during mitosis the Golgi apparatus behaves in 

 quite different ways (see Fig. 14, 80). Nucleolar extrusions take 

 place in some cases (adeno-carcinoma of the mouse), but such 

 conditions found in cancerous tissue cells can be also found in 

 j^erfectly normal tissues. 



Despite the considerable amount of data at his disposal, Ludford 

 is compelled to come to the following general conclusions : — 



" It has been pointed out that with our present microscopic 

 technique there is no means of distinguishing between a normal 

 and a cancerous cell. The wide range of pathological variations 

 are the morphological expression of the reaction of the cells to the 

 peculiar conditions of tumour growth. There is no pathological 

 state restricted to cancer cells alone, so that there exists for the 

 cancer cell no precise morphological diagnostic character of any 

 kind. 



H.A.M. 6 



