298 



The largest yam produced in 1914, was one of local origin, the 

 parent tuber having been found in the deserted garden of the Govern- 

 ment bungalow on the top of Bukil Timah; it weighed 17 lbs. 8 oz. 

 or almost 8 kilogrammes; and as it was still in full growth, when 

 dug, it would have attained considerably more, say, by January in which 

 month the plant of 1913 was still green. Next to it in weight was a 

 yam -<3fl Philippine origin which weighed 16 lbs. 9 oz. or 7513 grammes 

 (see page 299 figure 2.) The third tuber in size was also of Philip- 

 pine origin and weighed 12 lbs. 6 oz. or 5613 grammes. In appearance 

 it was almost exactly. as the tuber of the Bukit Timah plant, but 

 there was this difference between the plants that the stem of the 

 Bukit Timah plant produced a profusion of bulbils, whereas that 

 of the Philippine plant did not. The tuber which came fourth 

 in weight w^as from a Philippine plant numbered IO54, (page 299 

 figure I) ; it differed from the preceeding a little in the surface of the 

 tuber and in its foliage ; its weight was 9 lbs 13 oz. or 4450 grammes. 

 Plant no. IO42, (page 299 figure 5) produced a not altogether dis- 

 similar tuber weighing 7 lbs. 7 oz. or 3373 grammes. All these big 

 biWy- tubers except no. 1057, (page 299 figure 2) wcre without 

 purple sap. 



Attention may be called to the slight difference in shape between 

 the tubers 1054 (page 299 figure I) and 1042 (page 299 figure 5) in order 

 to make the comment that it has been man's endeavour in selecting 

 yams to obtain something which does not give great labour in 

 digging, i.e. something surface-rooting. P^rom such a point of view 

 no. 1042 (page 299 figure 5) is an improvement on no. 1054 (page 299 

 figure I), and both are an improvement upon the Bukit Fimah race 

 which buried itself to a depth of 28 indies. 



• . '.'Some of the deep burying yams are however very tender, and are 

 thought, by jungle tribes particularly, a much desired food, so that 

 they laboriously dig them out. One object therefore which man 

 must have haii in view in his work of selecting would be the preser- 

 vation of tlie delicacy of substance while getting rid of the deep 

 burying. Rumpf relates that in his time (1653-1720) in Celebes the 

 inhabitants had a way of circumventing the yams which was by com- 

 pelling them to grow through horizontal bamboos placed in the surface 

 of the soil. The modern use of such a device is unrecorded; but the 

 Philippine yams possess, in one little group, no tendency to bury, 

 though elongating considerably. For instance no. .956 (page 301 

 figure 3) recurved back and actually extruded the tip of its tuber from 

 the soil. No. 943 (page 301 figure 4) behaved similarly. Nos. 935 

 (page 301 figure 5) and 945 (page 301 figure 6) while differing slightly 

 also extruded their tuber-tips, and Nos. 1095 (page 301 figure I) and 

 960 (page 301 figure 2) instead of growing down, elongated more or 

 less horizontally, the larger to a length of 20 inches. 



Because of their great interest, all the tubers raised of this type 

 are here figured, though we may not have among them more than 

 three races. It may be remarked further that thty all had purple sap. 



