CANCEROUS TUMORS. 13 



figures, evidently drawn after nature, and is in every way 

 worthy of tlie most thoughtful consideration of the student of 

 cancer. 



Such, gentlemen, is an outline of the recent progress of our 

 knowledge of the structure of cancerous growths, and of their 

 relations to the surrounding parts. I have endeavored to seize 

 and present for your consideration the most salient }X)ints. In 

 so doing I have been compelled to omit all mention of many 

 worthy investigators. Perhaps you will think I have already 

 dwelt too long on this historical review, but before referring to 

 my own observations I would beg to speak for a moment of the 

 doctrines taught in two excellent German text-books, transla- 

 tions of which have recently been published in this country. I 

 refer to the surgical pathology of Billroth,* and the patho- 

 logical histology of Rindfleisch.f 



Billroth, who has himself contributed no little to the details 

 of our knowledge of morbid growths, adheres in all essen- 

 tial points to the views of Thiersch and Waldeyer ; while 

 Rindlleisch entertains opinions more nearly allied to those 

 of Classen. Rindfleisch admits that perhaps, in cancers involv- 

 ing glands, the glandular epithelium may undergo fissiparous 

 multiplication, and so contribute somewhat, though only, as he 

 thinks, to a moderate extent, to the formation of the cancer 

 cylinders. But he thinks that a far larger part is played by 

 migrated white blood corpuscles, which, instead of being trans- 

 formed into pus or connective tissue as in inflammation, 

 accumulate in the Ij-mphatic passages and are metamorphosed 

 into epithelium-like elements. I commend these instructive 

 and easil}' accessible works to your consideration, especially 

 that of Rindlleisch ; but I warn you that to read them with ad- 

 vantage you must do so by the side of the microscope. 



* General Surgical Pathology and Therapeutics. By Dr. Theodor Billroth. 

 American edition. New York, 187]. 



t A Text-book of Pathological Histology. By Dr. Edward Uindfleisch. Ameri- 

 can edition. Philadelphia, 1872. 



