CANCEROUS TUMORS. 11 



of the circulation in the tortuous veins, which in properly pre- 

 pared sections are found, as might be expected, to contain 

 great numbers of white corpuscles. The small-celled brood 

 first appears in the connective tissue stroma immediately 

 around the blood-vessels. Between these little lymphoid 

 cells and the large epithelial forms of the cancer cylinders 

 every transition can be observed. When we remember the 

 structure of connective tissue, and the manner in which Von 

 Recklinghausen has shown its little cavities and passages to 

 open into the lymphatic capillaries, we shall not be surprised 

 that it is in these, the nearest available cavities, that the new 

 elements accumulate and develop into the cancer cylinders ; 

 for Classen agrees with Koester that the cylinders lie in the 

 lumen of the Ijmiphatics ; he differs from him only as to the 

 source of the component cells. As to the assertions of 

 Thiersch and Waldeyer that the cancer cells are essentially 

 epithelial elements, and therefore can only be the progeny of 

 the horny layer of the embryo and of its derivatives, it 

 appears to him a generalization which the facts do not justify. 

 "I fear," he cries, "that in this way we shall attain a cellular 

 mythology before we shall have a cellular pathology." 



And here I pause for a moment to say, that in the latter part 

 of the year 1871, my own study of thin sections led me to the 

 conclusion that the migration of the white corpuscles played a 

 great role in the development of cancerous growths, and that, 

 at least in certain cases, the cancer cylinders were formed by 

 the transformation of these corpuscles, which first accumulated 

 in the lymphatic capillaries and the passages leading to them. 

 In April, 1872, in a brief report pul)lished b}' the Surgeon Gen- 

 eral,* I advocated this view, though not so exclusively as 

 Classen has done, for I could not avoid saj'ing that I was not 



* Report to the Surgeon General of the United States Army on the minute anat- 

 omy of two cases of cancer. By Assistant Surgeon J. J. Woodward, U. S. A. 

 Washington, D. C, 1872. 



