LEONARD DONCASTEIl, 1877—1920. 



The death 'of Leonard Doncasfcer at the age of 42 has stopped a career of 

 exceptional promise. He was a natural investigator, driven to research 

 hy the impulse of scientific curiosity, and his work will have a permanent 

 place in the history of genetics. Born at Sheffield, December 31, 1877, 

 the son of Samuel Doncaster, manufacturer, and his wife Emma Gertrude, 

 whose maiden name was Barber, both members of the Society of Friends, 

 he was one of the many naturalists produced by that body. Throughout 

 his life the Quaker principles governed his development and bearing towards 

 the world, an influence which naturally became marked during the period 

 of the war. He was sent to the Friends' Public School, Leighton Park, 

 Eeading (1890 — 5), going thence to King's College, Cambridge (1896), where 

 he took an open scholarship. Before coming up he spent six months at 

 Heidelberg, and thus had the great advantage — to a biologist — of some 

 knowledge of German from the start. In the Nat. Sci. Tripos, Part II, 1910, 

 he took a First, with a mark of distinction in Zoology, rarely given. 



Though a zoologist by formal choice, he might equally have been a 

 botanist. From childhood there was never any doubt as to the leading 

 purpose of Doncaster 's life. The problems of biology were always in his 

 thoughts, and the form in which they presented themselves was to him 

 indifferent. As a young student he was already a competent field botanist 

 and entomologist, with some knowledge also of the domesticated animals 

 and plants, much of which he had acquired in his father's weli-known and 

 beautiful garden. But, though his range was wide, anything like vagueness 

 or superficiality was quite alien to his composition. He liked knowledge 

 hard and clear; and his weaknesses were not those of the omniscient or the 

 expansive. Circumstances led him into academic zoology, but lie never lost 

 touch with these varied interests. Biology was probably to him, as to so 

 many modern naturalists, rather a challenge than a source of contemplative 

 enjoyment. A hint, which could be used in the attack, might come from 

 anywhere. 



After taking his degree he spent some time at the Naples Station 

 (1901 — 2). He had there two objects in view, the first being to make a 

 fresh investigation of the structure and development of Sagitta. In this 

 animal there is an ovary and a testis on each side of the body ; and since 

 the two organs, male and female, of each side arise directly by division 

 and differentiation of a single common mother-cell, there was a chance 

 of seeing something exceptionally interesting in the cytological phenomena 

 by which this process is accomplished, A useful paper on Sagitta was the 

 outcome of this work, but cytologically the material proved intractable. 

 His second purpose at Naples was to find out why such various and dis- 

 cordant results had been encountered by previous experimenters on the 



