George Henry Falkiner Nuttall FRS (5 July 1862 – 16 December 1937) was an American-British bacteriologist who contributed much to the knowledge of parasites and of insect carriers of diseases.

He made significant innovative discoveries in immunology, about life under aseptic conditions, in blood chemistry, and about diseases transmitted by arthropods, especially ticks.

In 1893 He published Hygienic Measures in Relation to Infectious Diseases, a book dealing with cleanliness, disinfection and fumigation in medical practice.

Working with Hans Thierfelder he developed methods for rearing guinea pigs under aseptic conditions, with no gut bacteria.

[1][8] During this period his interest in the role of insects in transmission of disease developed, which would continue to be a major topic of research.

[1] In May 1899 Nuttall travelled to Cambridge at the invitation of Clifford Allbutt, Regius Professor of Physic at the University, and gave a series of lectures in bacteriology.

A major topic was piroplasmosis and related malaria-like parasites transmitted by ticks, mainly in dogs, but also in other animals including humans.

This began in response to the practical problems with lice in the troops, but developed over the next few years into research on their biology and role in disease.

[5] Initially the humoral and cellular theories were seen as rival explanations of immunity, but it soon became clear that processes of both kinds occur and complement one another.

[21][22][23] Darwin's theory of Evolution - descent with modification - provided a theoretical basis for classification in biology, species within a taxon sharing a more or less recent common ancestor.

Classification based on morphology has two main limitations: difficulty in dealing with convergent evolution where similar forms arise in species that are not closely related; and an inability to provide a quantitative measure of relatedness.

[29][30] In 1900 Nuttall and Austen published a book reviewing the evidence for transmission of disease by Insects, Arachnids and Myriapods, which included a discussion of the mosquito theory of malaria.

Nuttall and colleagues carried out a survey of the distribution of the Anopheles mosquito in England, showing a concentration in the areas where malaria (ague) had previously been prevalent.

[33][1][34] Nuttall and Shipley subsequently published a series of papers in The Journal of Hygiene on the structure and biology of Anopheles (1901–1903), which represented the most detailed study on the topic up to that time.

Smith and Kilborne identified the parasite in Texas cattle fever, and established that it was transmitted by ticks, the first proven case of arthropod disease transmission.

[37][38] In a series of papers published with Graham-Smith in The Journal of Hygiene (1904–1907) Nuttall described the nature of the disease and the multiplication of the parasite in the blood of dogs.

Subsequent work with Seymour Hadwen led to the discovery that trypan blue was an effective treatment both in dogs and cattle.

Nuttall, carried out a series of studies that, as with many of his other researches, combined a theoretical and zoological approach with practical concerns.