350 THE CAUSATION OF DISEASE. 



tissue-potentialities. The carcinomata, however, have no such 

 simple structure ; but I have no hesitation in affirming that in 

 their case also the change is a backward one. Some patho- 

 logists have spoken of endothiomata and other hypothetical 

 kinds of malignant growth, and I doubt not that eventually 

 our classification of the malignant tumours will be less simple 

 than it is now. For the present I wish to leave all such 

 doubtful forms out of account, and to speak only of the well- 

 recognized and typical forms of cancer. There can, I think, 

 be little question that such forms belong to the glandular type. 

 This is very plainly shown in the case of the epitheliomata. In 

 the squamous variety the epithelial cells dip down just as in 

 the development of all open glands. All the intestinal open 

 glands are thus developed, not even excepting the liver ; but, 

 observe, the down-growing cylinders never become hollowed 

 out. ' The glandular tissue is, therefore, of a very crude, imma- 

 ture form — of a form like that which probably obtained in some 

 very remote form of ancestral life, for, at its first evolution, the 

 in-growing gland was almost certainly solid. In the cylin- 

 drical-celled variety a more perfect type of tissue is approached, 

 for the cylinders contain a distinct lumen; nevertheless, the 

 process is disorderly, and the gland-tissue, taken as a whole, 

 is decidedly imperfect. In the acinous forms of cancer the 

 glandular type is maintained, but it is distinctly of an erratic 

 kind, and the fact that the acini are generally crammed with 

 epithelial cells is probably due to the rapid multiplication of 

 these latter. But it is a noteworthy fact that in many instances 

 there is a distinct tendency to a regular arrangement of the 

 cells as a single layer on the walls of the acini, when the 

 true glandular nature of the tissue becomes manifest ; where- 

 fore we may say that the carcinomata consist of an immature 

 and disorderly form of gland-tissue. The change is, conse- 

 quently, a backward one ; it is not an evolution, but a disso- 

 lution, the affected tissues manifesting some one or other of 

 the countless potentialities locked up within them. 



I mentioned the dissolutionary nature of the malignant 

 change as an argument in favour of its being due to some 

 modification in E, for, so far as I know, rapid dissolution 

 cannot take place except by alteration of cell-E. Many pages 



