2() THE TONER LECTURES. 



secondary growths were found after death in the stomach 

 and spleen. The case is described in detail in Circular No. 

 3.* The photograph gives side views of several of the nucle- 

 ated cylinders, and of the connective tissue between them. 

 (One photograph, No. 48, shown.) 



The other photograph is taken from a scirrhus of the breast, 

 extirpated in March, 1871, the subsequent history of which is 

 unknown. (Surgical section, Army Medical Museum, No. 

 5903.) The cylinders are narrow as compared with those 

 shown in the last picture. (One photograph. No. 49, shown.) 



Towards the margins of a growing mammary cancer it is not 

 uncommon for the cylinders to be so slender and so tortuous 

 as to appear in thin sections like small elongated cell groups, 

 such as have been supposed to originate in the proliferation of 

 the connective tissue coriiuscles. A comparison of a number 

 of adjacent sections will show their real nature. Two views, 

 taken from one of the breasts described in my report to the 

 Surgeon General, will serve to illustrate this point. (Two 

 photographs, Nos. 50 and 51, shown.) 



In the case of cancer of the breast, as we have already seen 

 in epithelial cancers, there may be three explanations of the 

 genesis of the cancer cylinders, so far at least as they are new 

 formations. Either they are outgrowths from the epithelium of 

 the ducts and vesicles of the diseased gland, or they originate 

 by the transformation of the small-celled infiltration, which 

 here, as in skin cancers, is conspicuous in the connective tissue 

 stroma, or both these processes may contribute. A decision 

 between these possibilities is still more difficult than in the 

 case of skin cancers. In attempting the solution of the ques- 

 tion it is important to observe the behavior of the gland-ducts 

 and vesicles themselves in growing cancers, and to endeavor 

 to ascertain the transformations they undergo. Some of the 

 photographs shown this evening illustrate at least one of these 



* Circular No. 3, Surgeon General's Office, 1871, p. 2G6. 



