1909] BRIEFER ARTICLES 229 
the soil.” Being somewhat uncertain as to the intended meaning of this 
statement, I have learned by correspondence that Graves believes that in 
my paper I have committed myself to the notion (in the absence of con- 
clusive evidence) that the larger submerged and rooting water plants 
derive their mineral food exclusively from the soil, and that there is no 
absorption of mineral food by organs other than the roots. Such a notion 
I have never held and do not consider my paper as warranting or encoura- 
ging such an interpretation. My efforts to force certain species to live and 
grow in nutrient solutions and without a substratum were not continued 
to a satisfactory conclusion, and for that reason I remained noncommittal 
on the possibility of absorption by the other organs of the plant. 
My general conclusion was that certain species which were tried were 
found to be dependent upon their rooting in the soil for optimum growth 
and cannot survive a single season if denied a substratum of soil. 
Whatever the absorption by the organs other than the roots amounts to 
(in the species tried), it is so small that the species would probably become 
extinct if forced to depend upon it exclusively under otherwise natural 
conditions. 
Looking at section D as a whole we find that every paragraph is general 
in its scope and treatment. GRAVES tes four reasons for not placing 
too much emphasis “on the absorbing capacity of the root.”” One of the 
reasons is “‘the total lack of branches and slenderness of the roots.” I 
think any reader would infer that submerged plants have slender roots 
without branches. So far as I know the statement is correct so far as the 
“slenderness” is concerned but’in my paper (/. c.) there is a section on 
factors influencing the development of lateral roots 
Speculation as to the relative importance of absorption by the roots 
of submerged plants as compared with that in the case of land plants is of 
little value. I refer particularly to the statement by GRAvEs as follows: 
‘In brief, the absorption carried on by the roots of submerged plants and 
the importance of this function in the economy of the plant is much greater 
than is implied by ScHENCK—but, on account of the peculiar environ- 
mental conditions of submerged plants, it can never equal in importance the 
absorption of the roots of land plants.” 
Tf the submerged species are as dependent upon rooting in the soil ne 
my Tesults show, the so-called absorptive function of the root is a vital 
necessity and it certainly is not more than this for land plants —RAYMOND 
OND. 
