BY EUGEN HIRSCHFELD, M,D. 91 



cell is situated becoming weaker, affords an opportunity for its 

 multiplication and transformation into a real cancer. Although 

 nobody has yet seen this slumbering cancer-cell, and its existence 

 is purely hypothetical, our experience in other parts of pathology 

 does not tend to support the above explanation. Let us take, 

 for instance, consumption. The hereditary transmission of the 

 predisposition to this disease is admitted on all sides. Accord- 

 ing to the views just mentioned we naturally would be led to 

 expect by analogy that, owing to the great resisting power of the 

 organism, the predisposition would not operate until people had 

 become old, when they would succumb most readily to con- 

 sumption of the lungs. What do we find, in reality '? The 

 overwhelming majority of cases of consumption occur during 

 youth and early manhood. It is, therefore, to say the least, 

 improbable to contend that the increased prevalence of malig- 

 nant tumours amongst aged people is due to the weakened 

 resisting power of the organism. Moreover, I should like to 

 draw attention to the face that the persons generally affected by 

 cancer have, in every other respect, been up to the beginning of 

 their disease healthy and robust individuals. The relative 

 frequency of cancer among the farming community in Queens- 

 land seems to point in the same direction. 



Attempts have been made in the last few years to attribute 

 the causation of cancer to parasitic infection with Sporozoa, or 

 Cancer Amoebae. It is difficult to conceive why the Sporozoa 

 should limit their attacks to old people, or should be harmless 

 to persons below 30 years of age, although almost every other 

 infectious disease — acute or chronic — attacks, as you are aware, 

 with predilection young individuals. To call in aid a hypo- 

 thetical weakened resisting power is out of the question. We, 

 therefore, must content ourselves with having established the 

 curve of the distribution of cancer among the different age- 

 groups in the Australian Colonies, so that we may be able to 

 connect them with any other facts that may be elicited with 

 regard to this subject. It is perhaps of interest to mention that, 

 among the small number of cases of malignant new growths 

 which are occasionally found in childhood and early youth, the 

 majority affects infants or children below 5 years of age. The 

 reason for this occurrence is that some of these tumours are 



