History of Ceylon Botany. 377 



specially skilful in preparing microscopic objects, at a time when 

 students of the structure of cryptogams were so few in England 

 that many of his discoveries were overlooked and subsequently, 

 attributed to later Continental workers, his most important obser- 

 vations at this period were those on the conjugation and algal 

 nature of diatoms — organisms which had till then been generally 

 regarded as animals. This discovery led Montagne to dedicate to 

 him in 1845 the algal genus Thwaitesia. He worked also at 

 desmids and lichens ; but that he did not confine his attention to 

 cryptogams is shown by his communicating a list of the flowering 

 plants within a ten-mile radius of Bristol to Hewett Watson for his 

 'Topographical Botany.' He was also one of the early contributors 

 to the ' Gardeners' Chronicle,' one of his first discoveries with a 

 direct bearing upon horticulture being the raising of two distinct 

 varieties of Fuchsia from the two embryos in a single seed. In 

 1846 he became lecturer on botany at the British School of 

 Pharmacy and Medical School, and in the following year was, like 

 Watson, an unsuccessful candidate for a natural history chair in 

 one of the new Queen's Colleges in Ireland. 



Directly he reached Ceylon, which he never left till his death, 

 he devoted himself to the investigation of the flora of the island, 

 and for fifteen years he almost ignored his favourite Cryptogamia. 

 Until 1857 his duties were mainly scientific, and between 1852 and 

 1856 he contributed numerous descriptions, with drawings and 

 analyses, of Sinhalese phanerogams to Hooker's 'Journal of 

 Botany,' including twenty-five new genera. In 1857 the title of 

 his office was changed from Superintendent to Director, and he 

 became yearly more and more engrossed by the less congenial duties 

 of investigating the application of botany to tropical agriculture. 

 It is hardly surprising that the lay mind, becoming aware of the 

 absence of any adequate enumeration of Ceylon plants, and unable 

 to appreciate the thoroughness of Thwaites's method, should 

 grumble. Thus we find Sir J. Emerson Tennent writing in 1858: 

 ' Up to the present time the botany of Ceylon has been imperfectly 

 submitted to scientific scrutiny. .... It may be mentioned as a 

 fact which is much to be regretted, that, although botanists have 

 been appointed to the superintendence of the Botanic Gardens at 

 Kandy, information regarding the vegetation of the island is scarcely 

 obtainable without extreme trouble and reference to papers scattered 

 through innumerable periodicals. That the majority of Ceylon 

 plants are already known to science is owing to the coincidence of 

 their being also natives of India, whence they have been described ; 

 but there has been no recent attempt on the part of colonial or 

 European botanists even to throw into a useful form the already 

 published descriptions of the commoner plants of the island. Such 

 a work would be the first step to a Sinhalese flora. The prepara- 

 tion of such a compendium would seem to belong to the duties of 

 the colonial botanist, and as such it was an object of especial 



