BANISHING THE PLAGUES 



plague by fleas, and various cattle plagues and at 

 least one disease of the temperate zone, the Rocky 

 Mountain fever, by ticks. 



In recent years the study of tropical diseases has 

 become a special department of medicine, but the 

 laboratories in which the investigations are pvose- 

 cuted are not necessarily located in the tropics. In 

 point of fact perhaps the chief center of such studies 

 is at Cambridge University, England. The biologist 

 in charge of this department of investigation is Dr. 

 George H. F. Nuttall. His official position is that of 

 Quick Professor of Biology. Professor Nuttall's stud- 

 ies of the blood have given him international repu- 

 tation. In view of his professorship at Cambridge, 

 and the further fact that he is a Fellow of the Royal 

 Society, it is of peculiar interest to note that he is 

 an American. His chief work, however, has been 

 done in Germany and at Cambridge. 



The coveted honor of election to Fellowship in 

 the Royal Society was given Professor Nuttall in 

 recognition of a very remarkable series of blood tests 

 of which account has been given in another chapter. 

 A still more recent investigation of Professor Nuttall 

 has to do with a class of tropical animal diseases the 

 germs of which are transmitted from one animal to 

 another by ticks. The most important disease of this 

 class from an American standpoint is the cattle plague 

 known as Texas fever. 



The discovery that ticks transmit this disease was 

 made by an American, Dr. Theobald Smith, as long 

 ago as 1889, and a method was devised whereby the 

 animals were rid of the pests by being made to swim 



245 



