50 NOTES ON DIPTEROCARPS. 



cations as they could with what they had. Bentham for instance 

 in Bentham and Hooker's Genera Plantarunt, i, (1862) p. 190, 

 after saying that the calyx in fruit gives the best key, presented 

 an alternative on the structure of the flower: and Alphonse de 

 Candolle in his Prodromus, xvi, part 2. (1868) p. 604 took a 

 different line in classifying by the number of stamens. Heim, 

 much later (Recherches sur les Dipt ero car pacees, Introduction a la 

 Monographic generate de la Famille, Paris, 1892, p. 14), when 

 essaying to throw light upon the order by means of the microscopic 

 structure, wrote " the shape of the embryo is very variable, accord- 

 ing to the genera, — and this shape, wrongly neglected by writers, 

 may furnish generic characters of the highest importance : " But 

 Brandis in the Journal of the Linnean Society, Botany, xxxi, 1895, 

 p. 15, refused to allow importance to it, stating that the variability 

 is great even among species otherwise closely allied. I am with 

 Heim in thinking that there is a promise of utility in the study 

 of the embryo. 



Brandis' effort is the last that has been made at classifying 

 comprehensively the Dipterocarps of the World. He had long 

 been an Indian Forest Officer : but he did it as herbarium work, his 

 field knowledge of the order remaining limited to the relatively small 

 number of species found in India. Few will regard the result as 

 satisfying our need. 



Upon the botanists who live where Dipterocarps grow, now 

 rests the duty of collecting such details regarding them as the 

 Herbarium botanists have not had in full measure, and among the 

 details, as Heim has pointed out, are the structure of the embryo 

 and appearance of the seedling. Trimen, indeed, made some ob- 

 servations on the structure of the embryo of the Ceylon Diptero- 

 carps (Handbook of the Flora of Ceylon, i, 1893, pp. 112-138 and 

 his plates 13-15), but not comparatively between the species; and 

 Pierre in his beautiful Flore Forestiere de la Cochin-Chine,. Paris, 

 1888, plates 212-259, figured many embryos, but unfortunately 

 nearly always in a slightly immature state. I find consequently 

 in his plates indications rather than facts, and trust that some 

 day soon there may appear a botanist in Indo-China who will de- 

 lineate the seedlings and mature embryos of the Dipterocarps which 

 make so large a part of the forests there. 



Six ovules occupy in pairs the three chambers of the ovary 

 of any one of the Dipterocarps. Out of the six except in cases 

 which are rare, and of which a few have been recorded, one only 

 develops into a seed. Brandis who in 1895 drew together the ob- 

 servations of earlier writers on the order, was able to cite but 

 three species in which twin seeds had been found, namely Diptero- 

 carpus condorensis, Pierre, Dipterocarpus alatus, Eoxb., and Dry- 

 obalanops aromatica, Gaertn. f. (Engler's Pflanzenfamilien, iii, 

 part 6, p. 251). To these Mr. B. Sen-Gupta (Indian Forester, 

 xliv, 1918, p. 372) adds Shorea robusta, Boxb.. with the remark 

 that twin seeds are not infrequent. 



Jour. Straits Branch 



