Vasily Danilewsky  Vasily Iakovlevich Danilewsky (variously spelled Vasili Yakovlevich Danilewsky or Vasili Yakolevich Danilevski or Vasily Yakovlevich Danilevsky, Russian: Даниле́вский Васи́лий Я́ковлевич) ( – 25 February 1939) was a Ukrainian-born Russian physician, physiologist and parasitologist. He was professor of physiology at University of Kharkiv and then at Kharkiv Medical Institute. He helped to establish the Danilevsky Institute of Endocrine Pathology Problems which he directed until his death. Danilewsky made important works in physiology, particularly in neurobiology. He was the first to give comprehensive description of nerve impulse in the brain of dogs. He also worked on the physiological responses of hypnosis in animals and humans. He was one of the pioneers in study of insulin action. However his most well known contribution is in parasitology. He was the first to investigate systematically on blood parasites of vertebrates such as birds, reptiles, and amphibians. He is the binomial authority of a number of bird parasites. His paper titled "About Blood Parasites (Haematozoa)" published in 1884 in the "Russian Medicine" journal is regarded as the foundation of modern parasitology in bird malaria and other protozoan infections. A species of blood parasite in bird "Haemoproteus danilewskyi" is named after him. Danilewsky was born in Kharkiv (was under Russian Empire, now Ukraine), and was educated there. He graduated from the University of Kharkiv in 1874, and earned his doctoral degree in 1877, at the age of 25, upon the thesis "Investigations into the physiology of the brain". He was professor of physiology at the University of Kharkiv during 1883 to 1909 and 1917 to 1921. From 1921 he transferred to Kharkiv Medical Institute. In 1927 the Russian Academy of Sciences established Danilevsky Institute of Endocrine Pathology Problems, which he directed until his death. Danilewsky was one of the pioneers of neurobiology. He was the first to describe the nerve impulse system in the brain of dogs. However his most notable works were in parasitology. In 1884 he was the first to observe the species of "Haemoproteus", parasitic protozoan in the blood of birds, and established the order Haemospororida for it.