TWO TYPES OF PROLIFERATION IX 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. 1 



It is evident that while these investigators take cognizance of the 

 rleep-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 for 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, 2 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 years 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 

 growing 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, 3 

 afforded Le Blanc and others a condition for study such as exists at 

 the present time. 



STEM PROLIFERATION, CHARACTERS, AND FUNCTIONS. 



Conclusion* 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. 4 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 isr>, p. 

 08-69, 1910. 



- Ileadden, W. P. Alfalfa. Colorado Agricultural Experiment Station, Bulletin :',o, 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. 



4 Blinn, V. K. Op. cit. 



[Cir. 115] 



