1885.] Br, Beck, BathoJogical Evolution. 37 



suffice to supply us in this connection with as much scope for observa- 

 tion as thousands of years in connection with higher organisms. 



More than a year ago, in a communication I made to the South 

 African Medical Society, I contended for a possible de novo origin of 

 small-pox. More than two years ago I read before the members of this 

 Society a paper in which I attempted to explain the cause of the camp 

 fever of Kimberley. 



In both papers I followed a line of reasoning which assumed the 

 possibility of the development of '' disease germs" where before none 

 existed, and where special conditions had arisen to favour their de- 

 velopment. 



Since then I have closely watched such disease phenomena as have 

 come under my notice, and my observations have only strengthened 

 my conviction as to the variability ol germs. 



Last year an epidemic of pneumonia occurred in Worcester, where 

 I at that time practised. 



It is not necessary for me to go into modern ideas with regard to 

 this disease, but I may by way of explanation say that a large school 

 of pathologists now regard it no longer as a disease of the "lungs" 

 proper, but as a fever having for its distinctive character certain 

 changes in the lungs, just as in the same way small-pox is a fever 

 which has for its distinctive charater certain changes in the skin. At 

 the same time with this epidemic occurred an epidemic of rheumatic 

 fever and an epidemic of remittent fever. 



The last we all recognise as a malarious fever. Bheumatism, 

 Maclagan, one the greatest authorities at the present time on the 

 subject, and the collaborator of the salicin treatment of the disease, 

 declares to be also malarious in origin. If we agree with him, and I 

 for one do agree with him, then the remittent and rheumatic fevers 

 must have more or less allied conditions causing them, and be subject 

 more or less to the same casual laws. Now in one house a man was 

 attacked with pneumonia, his wife with remittent fever, — both fell ill 

 at the same time, both had typical attacks. The wife suffered from 

 chest complications of a decided kind, a significant fact when taken in 

 connection with the pneumonia of the husband. These passed off 

 after a while. In another house one child developed pneumonia, 

 another child rheumatic fever. Both fell ill at the same time, both 

 had typical attacks. The thought suggested itself very forcibly that 

 the simultaneous occurrence of a pneumonia in the one house with the 

 malarious remittent fever, in another house with the malarious rheu- 

 matic fever, was an indication that, in some way or other, there was 

 an associated causal condition for the three different diseases. 



At Kimberley I am assured, on the. best of authority, that of Miss 

 Schreiner, a lady of the most remarkable powers of observation, who 

 devotes her entire energies to the care of the sick, and charitable work 

 of a like kind, that the natives almost invariably develope "pneu- 

 monia " after a heavy fall of rain. 



Now it is well-known that natives, almost everywhere, are not ex- 

 tremely susceptible to ordinary malaria, and the thought occurs that 

 here, under circumstances unfavourable in the native to the develop- 

 ment of an ordinary malarious fever, conditions which are known to 

 be favourable for the development of the malarious germ become 

 favourable for the production of pneumonia. I mention this by way of 

 additional evidence in support of my hint as to the probable identity 



