In collaboration with H. Thierfelder 

 (1895-97), he carried out the first 

 successful experiments on life under 

 aseptic conditions. In these investi- 

 gations, guinea pigs delivered by 

 Caesarean section were kept alive and 

 fed in a specially devised chamber under 

 bacteria-free conditions. 



In 1897, Nuttall turned his attention to 

 the role of arthropods in the spread of 

 disease, a subject to which he devoted 

 his later life. In 1899, he published 

 his well-known paper "On the Role of 

 Insects, Arachnids and Myriapods as 

 Carriers in the Spread of Bacterial and 

 Parasitic Diseases of Man and Animals," 

 which contains an exhaustive critical 

 and historical review of the entire 

 subject. Soon afterward (1900-01), he 

 became interested in the history of 

 malaria in England and in collaboration 

 with L. Cobbett, T. Strangeways, and 

 others undertook a survey of the distri- 

 bution of the genus Anopheles in England. 

 He found that three species of these 

 mosquitoes were in all districts that 

 were formerly malarious. The disappear- 

 ance of malaria in England was therefore 

 not due to the extinction of Anopheles . 

 In collaboration with A. E. Shipley, he 

 carried out an important investigation 

 on the structure and biology of 

 Anopheles , which is still considered a 

 classic. 



About the same time (1901), Nuttall 

 turned his interest to precipitin 

 reactions. He devoted the next 3 years 

 to studying the application of the 

 precipitin reaction to phylogenetic 

 relationships among vertebrates. In 

 1904, he published his classic mono- 

 graph "Blood Immunity and Blood Rela- 

 tionship," incorporating the results of 

 an extensive investigation of precipitin 

 tests carried out on the blood of about 

 600 species of animals. This investi- 

 gation clearly established the correla- 

 tion between the antigenic relationships 

 of animal sera and the zoological 

 relationships of the species. It threw 

 a new light on the study of the phylo- 

 genetic relationships in the animal 

 kingdom and provided also a new method 

 for identifying the character of minute 



traces of blood, a procedure that has 

 had notable applications in forensic 

 medicine. 



After the publication of this monograph, 

 Nuttall began his investigations on 

 diseases transmitted to animals by 

 ticks. By means of infected ticks 

 ( Haemaphysalis leachi ) sent to him by 

 C. P. Lounsbury from South Africa, he 

 succeeded in infecting dogs with the 

 agent of piroplasmosis, a disease unknown 

 in England. This was the first case of 

 investigating a disease imported by an 

 infected vector. An important result of 

 this study, which had great economic 

 importance, was the discovery of the 

 curative property of trypan blue for 

 piroplasmosis in dogs, cattle, and 

 sheep. This study was followed by an 

 extensive investigation of the anatomy, 

 biology, life history, and systematics 

 of ticks, carried out in collaboration 

 with C. Warburton and L. E. Robinson. 

 The results of these investigations are 

 incorporated in numerous papers and in 

 the monographic study of ticks that 

 occupied him on and off during the 

 remaining years of his life. During 

 this investigation Nuttall acquired a 

 very large collection of ticks from all 

 parts of the world, at that time the 

 largest in existence and rich in type 

 specimens. 



Most of his research interest during and 

 after World War I was in the study of 

 the Anoplura, their life history, 

 biology, anatomy, and the problems of 

 combating the spread of these parasites. 



In his early life Nuttall had traveled 

 in Mexico, Cuba, and North America, and 

 it was probably during this period that 

 he became interested in natural science. 

 His uncle, Tiburcio Parrott, gave him 

 his first microscope and started him in 

 making and preparing microscopic slide 

 mounts of all varieties of animals and 

 plants. This was perhaps the initial 

 event in Nuttall 's scientific career. 



Nuttall 's scientific work shows that he 

 possessed the attributes of the acute 

 observer, the experimental scientist, 

 and the naturalist to a remarkable 



