TWO TYPES OF PROLIFERATION IN ALFALFA. 5 
The Mongolian alfalfa, which proved to be the hardiest under the severe 
test at Dickinson of any of the newly imported strains, was found both there 
and at Stockton, Kans., to have crowns more deeply set in the soil than other 
varieties. It seems likely that this adaptation, if it may be called an adaptation, 
is of importance in giving the tenderest part of the plant.the needed protection.’ 
It is evident that while these investigators take cognizance of the 
deep-set crowns they fail to find rhizomes or underground stems pro- 
duced from the plants, or at least to note their presence. In their 
discussion of the root system of the Grimm variety they recognize 
only the ability of this strain to recover after the taproot has been 
broken off 4 to 8 inches below the surface, and state in this connec- 
tion that “this condition has suggested the possibility that the long 
endurance of stands of the Grimm strain may be due in some 
measure to the capacity fer putting out new roots and reestablishing 
itself after the taproot has been broken.” This statement is in- 
tended in no wise to convey the idea of proliferation, but only of a 
reestablishment of the original crown. Headden hints of this in 
mentioning the old method of transplanting mature plants and the 
continuation of gopher-eaten plants in some soils,? but he also did 
not have in mind the production of new plants vegetatively from 
stems or roots. 
Just why the production of rhizomes and underground stems in 
alfalfa was lost sight of until the last few vears is hard to explain, 
but the fact that they were observed at about the same date by sev- 
eral investigators working independently is very largely due to the 
comparatively recent increased interest in breeding and selection 
and the introduction of Medicago falcata and other alfalfas. The 
erowing of plants in rows and hills in connection with breeding 
furnishes ideal conditions for rhizome development, and the intro- 
duction of new alfalfas furnishes forms in which rhizomes are very 
commonly produced. The practice of growing alfalfa in rows and 
hills, strongly advocated in Europe in the time of Tull and Harte,’ 
afforded Le Blanc and others a condition for study such as exists at 
the present time. 
STEM PROLIFERATION, CHARACTERS, AND FUNCTIONS. 
Conclusions of other investigators.—In his study of the relation of 
type to the hardiness of alfalfa Blinn found some very important 
differences between the type of crown and the stooling habits in 
certain hardy and nonhardy strains.* He states that certain of the 
1 Brand, C. J. and Waldron, L. R. Cold resistance of alfalfa and some factors influenc- 
ing it. U. S. Department of Agriculture, Bureau of Plant Industry, Bulletin 185, p. 
68-69, 1910. 
2 Headden, W. P. Alfalfa. Colorado Agricultural Experiment Station, Bulletin 35, p. 6, 
1896. 
3 Harte, Walter. An account of Some experiments tending to improve the culture of 
lucern by transplantation. Essay II of his Essays on Husbandry, ed. 2, London, 1770, 
illus. 
4Blinn, P. K. Op. cit. 
[Cir. 115] 
