18 



CASSAVA. 



was impracticable to take up the chemical study when the crop was at 

 the height of its maturity, the analyses not being made until the last 

 of December, which is far past the season for cassava in that section. 

 The known extreme bitter varieties of the previous year had been 

 eliminated in the seedlings produced, but owing to the loss of all the 

 canes of that year's crop through rotting during the winter a new set of 

 canes, of the same varieties, was obtained from the Miami station. This 

 new importation of canes and the seed from the previous Biloxi crop were 

 planted together at the latter station for the second year. This change, 

 combined with the delay in making the chemical study, the roots being 

 already in an advanced stage of deterioration, makes the results hardly 

 comparable with those of the previous year, and, as would be expected, 

 they do not accord, and add little to the knowledge of the effect of 

 environment upon the hydrocyanic-acid content of the crop. The 

 analyses, made according to the same methods as in the previous } r ear 

 and by the same analyst, are tabulated in Table IV. 



TABLE IV. Hydrocyanic-acid content of cassava grown at Biloxi, 1905. 



a The supplemental numbers and letters in connection with the original pedigree numbers indicate 

 ilings from that strain, the letters representing a later planting. 



The entire series given in Table IV is below the semibitter standard 

 with the one exception of a very small plant, which perhaps had a 

 maximum cortical layer for the content of starch. 



In the eight seedlings obtained from the original plant No. 9674 only 

 one, with a content of 0.007 per cent, approached the amount of hydro- 

 cyanic acid in the parent plant, which contained 0.011 per cent in 1904 

 (see Table III, page 15). One seedling from No. 9676 exceeded the 

 parent plant in hydroc} 7 anic-acid content; one from No.,9678 practically 

 equaled the parent plant of 1904, and one from No. 9681 doubled the 

 hydrocyanic-acid content of the parent plant and became bitter. The 

 remainder of the seedlings did not exceed the parent plants in the per- 



