— 194 — 



way throLigh the difficulties myself. Before ail it was necessary to décide 

 upon the sélection method which had to be adopted and particularly upon 

 the applicability of pedigree-culture; and to this purpose 1 had to study 

 the floral ecology and the effects of self-pollination, as well as the early 

 developinent of the sexual cells, the fecundation and the fruition stage. 

 Secondly, I had to work out a booking System, specially adapted to the 

 description of the tea plant, and to establish extensive registers that were to 

 contain minute accounts af ail the plants selected, of ail the results effected, 

 shortly, of ail the opérations performed, in such a way that my successors 

 should hâve at hand ail information wanted. Beyond thèse two principal 

 objects, attention had to be paid to ail questions or practical matters 

 connected with the work of improvement labor, and this part of my charge 

 turned out not an unimportant one. 



I hâve thought it indispensable, before 1 commenced to communicate 

 the results of my work proper, to résume ail the facts known about the 

 varieties of the tea plant, and those about their geographical distribution, 

 in an historical sketch, and to draw spécial attention to anything in this 

 review valuable for tea sélection As such a critical essay on the origin of 

 an important crop plant does not exist as yet in the case of tea, that is, 

 not critical in the sensé of modem genetical science, 1 think it may be 

 valued as such. 



It is this first division that I hère submit to the reader. 

 - ' The second and perhaps the third division will be devoted to the 

 researches and performances, both scientific and practical, with a more 

 direct bearing on the breeding purposes pursued by my investigations. 

 They will be published as soon as the translation will be ready. 



l may hère add some bibliographical notes with référence to the 

 changes which the original paper in Dutch has undergone in this English 

 édition. ') Taken as a whole, the two parts issued hère completely cor- 

 respond with the first couple of chapters in my dissertation. 1 hâve not, 

 however, given an exact translation of the latter, but recast it, presenting 

 the same facts but frequently in a new séquence or supplemented with 

 new data. 



As to those additions, 1 specially refer to the account of tea (wild 

 tea!) in Tong-king; to three novae species of Camp///a published in 1918; 

 to the critical synopsis of the species of the genus Came///a,- to a complète 

 enumeration of the tea spécimens contained in the herbariums of Kew, 

 Berlin, Singapore and Buitenzorg 2); to Sir George Watt's discovery 

 on Browne & Bulkley's tea sample of 1700; and to some interesting 

 quotations from literature enumerated in the bibliography. 



') The cytological results of my researches on the floral ecology of the tea plant were 

 recorded both in my dissertation (1916) and in the paper: „Sur le développement 

 des cellules génératrices de Camellia theifera (Griff.) Dyer", Annales du Jardin 

 Botanique de Buitenzorg Sér. II, Vol. XV (1916), p.l. 



2) Those of Leyden. Utrecht and Calcutta will be published in the next division of 

 this paper. 



