133 



To indicate the relative starch value of Creole varieties and the new 

 Colombian varieties recently reported on (Bull . Vol. I p. 37) the aver- 

 age of the six varieties grown at Hope is compared with that of the 

 best six of the Colombian varieties. 



Grown under very similar conditions of soil and climate there is a 

 decided advantage in favour of the Colombian Cassavas, both as regards 

 starch, glucose and total solids. The ' Brown Stick' is practically on 

 an equality with ' Governor Hemming' (the best Colombian variety) 

 as regards starch but contains ten times as mucb Prussic Acid. 



We have not yet obtained data as to the agricultural yields of these 

 varieties. Clearly the relative value of the sweet and the bitter as a 

 source of starch lies entirely in the yield per acre and not in the in- 

 trinsic superiority of the best ' bitter' over the best ' sweet' in starch 

 content, 



As an article of food, of course, the Colombian non-poisonous Cas- 

 sava is beyond all question of rivalry. 



Hydrocyanic Acid in Cassavas grown at Hope. 



All the varieties grown at Hope are Bitter, the variety " Bobby 

 Hanson" having the lowest proportion of Prussic acid j*^ 



The results of the estimanon of the Frussic acid in the cortex and 

 the inner portion of the tubers are given in the foregoing table. 



For seven days a nearly uniform production of Prussic acid took 

 place when the sliced tubers 'were placed in water. The water was 



