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1906] BRIEFER ARTICLES 143 
organs normally appear only after the cells from which they arise have 
passed through their period of most rapid growt 
It would seem that the poor soil, by inhibits branch growth and 
causing the enlargement of cortical cells, may render the root system unable 
to carry on an adequate amount of absorption for normal growth, and that 
this fact may be the main clue to an explanation of the stunted tops in such 
cases. That the inadequacy of the stunted roots is in regard to the water 
supply rather than to that of salts, is indicated by the fact that in distilled 
IG. 4.—Roots grown in Takoma soil Fic. 5.—Roots grown in Takoma soil 
with 10,090 p-p-m. manure. with 40,000 p.p.m. manure. 
water, for the first two or three weeks, a better growth of tops is obtained 
than in the natural Takoma soil. 
Determination of the relation of the dry weight of the root system to 
the nature of the soil was deemed advisable, but a number of tests yielded 
only negative results. The dry weight of the complete system was found 
to be practically the same from all of the soils. The variations were 
always irregular. This may, of course, be partially due to the fact that, 
while it is manifestly impossible to obtain anything like the entire root 
System of one of the better cultures (owing to the extreme fineness of the 
branches and their adhesion to the soil particles), yet from the poorer 
cultures, where branches are short and few, a much larger part of the 
System is obtainable—Burton Epwarp Livincston, The University of 
Chicago, March 5, 1905. 
