282 Britain's Heritage of Science 



Although George James Allman (1812-1898) was Pro- 

 fessor of Botany at Dublin, he achieved his most marked 

 success as a zoologist. He left Dublin in 1856 on his 

 appointment to the Regius Professorship of Natural History 

 in the University of Edinburgh. He was, like so many men 

 of science, a good artist, and had exceptional skill in drawing 

 on the blackboard, and was a very popular lecturer, and he 

 took especial pleasure in taking his pupils on dredging 

 expeditions in the Firth of Forth and inducing them to 

 study marine organisms in the living state. His great work 

 on the Gymnoblastic Hydrozoa, published by the "Ray 

 Society, is stated by his biographer to have been without 

 doubt the most important systematic work dealing with the 

 group of Ccelenterata that has ever been produced. " The 

 excellence of the illustrations alone would almost justify 

 us in placing this work in the first rank of zoological treatises." 

 But he was equally an authority on certain groups of Polyzoa, 

 and it should be recalled that he it was who invented the 

 terms " ectoderm " and " endoderm," besides a great many 

 other useful expressions, such as " ccenosarc," " tropho- 

 some " and " gonosome," and many others. But above all 

 he did much to clear up the difficulty of defining species in 

 the Ccelenterata. 



Thomas Henry Huxley (1825-1895), a few years younger 

 than Wallace, was, as we have seen, another of Darwin's 

 supporters. He started life as a surgeon and, like Darwin, 

 owed much of his early reputation to a sea voyage. He 

 made a four years' cruise in H.M.S. Rattlesnake, 1846- 

 1850, during which he especially devoted himself to the 

 study of marine organisms. He was the first to dissociate 

 the hydrozoa from the star fishes, and the parasitic worms 

 and the infusoria, which had formed portions of Cuvier's 

 old group Eadiata. He did much to clear up the relations 

 of the Medusa to the Hydroid, and he dwelt especially on 

 the two -layered condition of their body wall, pointing out 

 its analogy with the gastrula. Shortly after his return to 

 England in 1850, he was elected a Fellow of the Royal 

 Society at the unusually early age of 26. 



As a morphologist, Huxley made immense advances. 

 Apart from his work on Coelenterates, he investigated the 



