379 



l)i:i:i' coixc; tchkks. 



/}rcji-;/oiii</ hihcrs {(IcsccinHini rrr/iralli/ and floH(/ah'(l) 

 irilhoiil uprisiiif/ shools. iiol r.rliihilitn/ hruiniiiij. nor hrancliin(/, — 

 sncli. Ix'cause their cliaractt'rs aj)iH'ar ancestral, we start with. On 

 plate 1 to the left of the jiietre measure, whicii makes a division 

 clown tlie centre are ti<j:ure(l three tiihers of race \o. 1G2. The 

 leii,u-th attained was just one metre or :V.) inches. Tliere was jio 

 llattening, and the even surface was very fret' from rootlets. The 

 skill was of a particularly dark hrown: witli just under it a layer 

 of the flesh holding magenta sap: the inner part of the flesh was 

 quite white. Tlie first parental tuljer of this race was one collected 

 for the writer by Bahu H. K. Das on the south face of the Khasia 

 Hills under Cherrapmiji and he reported that the-Kliasias use 

 the tuber eurried. and say that it is irritant raw. The largest 

 tuber in 1916 weighed 10| lbs. (4763 grammes), and the average 

 weight was 6^ lbs. {2^-\o grammes). 



In the collection there are other siniihii- I'accs. but only one 

 of them can as yet be reporte<l on. namely No. I 10 from Fiji. It 

 ))ossesses a similarly smooth skin, but of a lighter eolour. The 

 average return in 1916 was similar, namely 6 lbs. 11 oz. (3033 

 grammes). 



Of characters, which are among those considered secondary, 

 these two also proved to be similar in that they possess rounded 

 auricles to the largest leaves, but the degree of roundness so far 

 observed difl^ers : the second exhibited prickles on the stem, but 

 neither up-growing fleshy shoots, and both have some magenta sap 

 in the surface of the tuber, and both are without it in the vegetative 

 parts. Thus they Avere found closely related although not identical. 



The figures of production show them no better than races with 

 short tubers : and unless it may be for a delicacy in the deeply 

 buried parts of the tubers as a consequence of being grown remote 

 from the air* (an effect akin to that produced by earthing up celery 

 for instance) there appears no advantage in cultivating them where 

 races with shorter tubers could be raised. 



Deep going tubers, (a.s- the last tiro), but with a tendency to 

 branch. The jslui Xo. 186 figured on the right half of the upper 

 })art of Plate 1 differs from that on the left in a tendency to 

 branch. The depth to Mdiich the roots w^ent was almost the same, 

 but they were not so easy comparatively to dig out unbroken on 

 account of this branching. The surface was less smooth and 

 carried more small rootlets than that of N^o. 162. Under the skin 

 there was no magenta sap : and the flesh in the interior was yellow- 

 ish. Cooked, tlie race api)eared a good one: but comparative 

 methods of judging comestible value with regard to these _yams 

 have yet to be devised. The yield of the largest tuber was l4 lbs. 

 2 oz. (64U7 grammes) and the average for the five plants was 8 lbs. 

 15 oz. (40.54: grammes). 



* The Afon or Yellow Yam of Jamaica produces a bitter flavor in any 

 parts of its tubers exposed to the air (Harris, in Bull. Dcpt: Agric. Jamaica, 

 1909, p. 4). 



