54 rnocEEBixGS of the 



KiciiABD AssiiETOx, D.Sc, F.E.S., I'.Z.S. — By tlie death of 

 Dr. Asshetou in October ]1)15 the Linneaii Society lost a brilliant 

 member. Dr. Assheton belonged to that sadly dwindling band of 

 enthusiasts, who, being raised by the possession of adetjuate 

 private means above the necessity of a constant struggle for their 

 daily bread, are content to devote all their life and energy to 

 biological research. Although he held several most inadequately 

 remunerated teaching posts during his life, his object in doing so 

 was mainly to vitalize his research by the opportunities which 

 they afforded him of coming into contact with younger workers 

 and students. 



Dr. Assheton was born at Downham Hall, in Lancashire, in 

 1863. He was educated at Eton and afterwards at Trinity 

 College, Cambridge. He took his degree with liist-class honours 

 in Natural Science in 1886, one of his principal subjects being 

 zoology. After his degree he devoted himself to research in 

 embryology, for at that time the School of Comparative Embryo- 

 logy, founded in Cambridge by F. M. Balfour and carried on 

 after his death by Adam Sedgwick, was at the height of its 

 development. 



In 1889 he became demonstrator in zoology in the Victoria 

 University, Mnnchester, under Prof. !Milnes Marshall, and held 

 this post until ProF. Marshall's death in 1893. "Whilst at 

 Manchester he produced in conjunction with his colleague 

 Dr. Kobinson his first original memoir. This dealt with the fate 

 of the prnnitive streak and its equi\alent in the Prog. In this 

 paper we catch a glimpse of the principle which governed all 

 Dr. Assheton's subsequent research, viz., the effort not to be 

 content with describing appearances but to penetrate to the 

 analysis of the p^-ocesscs which are the acti\e agents in develop- 

 ment. It was demonstrated that the tail of a vertebrate is an 

 organ which owes its existence to a secondary zone of growth, 

 and is not a part of the body left behind by an imaginary and 

 impossible movement of the anus forwards in relation to the other 

 viscera. 



After leaving Manchester Dr. Assheton settled at Grantchester, 

 near Cambridge, where the remainder of his life was spent. 

 A long succession of valuable researches was carried out by him 

 in his private laboratory. For a while he devoted himself to the 

 difficult subject of mammalian embryolog}-, and he investigated 

 the early stages of development in the Sheep, a most costly piece 

 of research. He was led to a view of the early development of 

 3Iammalia w ith which we cannot agree : for he regarded the 

 layer of cells forming tlie wall of the blastodermic vesicle as 

 endodermic, instead of being ectodermic as the majority of 

 embryologists held it to be. Thereafter he undertook a series 

 of valuable experimental work on the development of the Chick. 

 He devised a method of opening the egg and keeping the embryo 

 alive, so that its growth could be watched and measured with 

 respect to fixed marks. By this m ork he extended and coiiiirmed 



