PROTOZOA AXD THE CANCER PROBLEM 205 



manifestations and in the reanimation of their hitent division energy 

 Hes the cause of from five to six deaths from cancer in every hundred 

 deaths from all causes. 



The carcinoma cell biologically is a perfect vital mechanism 

 endowetl with far greater power of resistance than normal cells, a 

 resistance which enables it to withstand long exposure to licpiid 

 air, or long periods apart from the sources of nourishment. In 

 reality it is no longer an ei)ithelial cell; something has changed it 

 from such a physiologically vml)alanced unit, subject to the coordi- 

 nating control and regulation of the organism, into a physiologically 

 balanced cell, uncontrolled and unregulated. Functionally, it is a 

 more perfect type than its orderly associates of the epithelium from 

 whence it springs; it takes in and assimilates abundance of food, 

 grows rapidly, especially when near the source of food, and repro- 

 duces its like by means of the same complicated processes of mitosis 

 that characterize normal cells, although it does not become differen- 

 tiated into organs, as do embryonic cells. "In short, it is a complete 

 organism in itself, simulating in many ways the parasitic protozoon, 

 but differing in some of the most important respects connected with 

 the continued life of the latter." (Calkins, 1908, p. 286.) 



By this continued cell division masses of tissue are formed which 

 grow out into lymph channels, pressing into spaces wherever found, 

 mechanically obstructing the normal activities of surrounding tissues 

 and organs, or breaking through such tissues, and ever giving off small 

 trroups of free cells which mav l)e carried bv the blood to various parts 

 of the body, there to set up independent growths (metastases) and to 

 become new centres of malignant activity. With the local disturb- 

 ances caused by such al)normal growths, many normal cells are killed 

 for lack of nourishment, or by poisonous degenerative matters of one 

 kind or other, while the cancer cells themselves undergo hyperplasia 

 and hypertrophy through lack of food, pressure, or natural resistance 

 of the victim. The march of cancer, therefore, is invariably accom- 

 panied by multitudes of degenerating cells, leukocytes of all kinds, 

 blood j)latclcts, and the like, and these difl'erent structures are the 

 things which, in various stages of involution and degeneration, have 

 been interpreted as "coccidia," "amebiv," "X-boclies," or, more 

 specifically, as "stroml)odes" (Sjobring), "Uhopalocephalus car- 

 cinomatosus" (Korotneff. '93), "Cancriameba macroglos.sa" (Eisen, 

 '00), 'Tlistosporidium carcinomatosum" (Feinberg. '03), or as other 

 "organisms" witii resounding names, the "cause" of cancer. 



Little interest is excited at the present time by description of such 

 cell inclusions in cancer, and investigators, on the whole, are content to 

 regard all such structures as degenerations or products of the disease 

 rather than its cause, and with this change in attitude the ])r()blcm of 

 cancer has passed from the descrij)tiv(' into the nuich more fruitful 

 stage of exjx'i'imental research. 



