42 Journal of Agricultural Research voi.iv, no. i 



leaves. A considerable portion of the ether extract is, of course, coloring 

 matter and not true fat. The percentages of crude fiber are not high, 

 from 6 to ID per cent being fairly constant for all samples. The same 

 statement applies to the pentosans. Iridaea sp. (a rockweed) is excep- 

 tional in this respect, having less than i percent as pentosans. Numer- 

 ous attempts were made to estimate by the mucic-acid method the 

 proportion of galactans present, but in most cases entirely untrustworthy 

 results were obtained. The method was found to be inherently unre- 

 liable and especially unadaptable to materials of this type. Approxi- 

 mate results were obtained for the Pelagophycus and the Iridaea, the 

 former yielding mucic acid equivalent to 3 per cent of galactan, the 

 latter 10 per cent. 



