354 The Effect of Potassium Salts on Dactylis glomerata 



potassic fertiUsers reduced the strength of mechanical cells in the early 

 stages of growth. This conclusion however would not hold if potassium 

 salts affected the composition of the wall. 



From these results it is concluded that the rigidity of plants supplied 

 with potassium salts is not the result of anatomical strengthening, but 

 must be attributed to other causes, such as the influence of the salts on 

 the physiological condition of the plant, or on its chemical composition. 



This work was carried out partly in the Botanical Department of 

 the Royal Holloway College, partly at Rothamsted Experimental 

 Station, and I desire here to express my gratitude to Professor Benson 

 and Dr E. J. Russell for their helpful criticism and advice during the 

 course of the investigation. 



REFERENCES. 



(1) H. J. Patterson. Maryland Experiment Station, Bulletin 89, June, 1903. 



(2) LoEW. U.S. Dep. Agr. Bur. Plant Ind., Bull. 45. 



(3) R. P. Weight. Report of West of Scotland Agric. College, 1896, p. 31. 



(4) Close, White and Ballard. Maryland Stat. Bull. 127, pp. 243-263. 



(5) CoPELAND. Bof. 6az. 1897, pp. 399-416. 



(6) Kissel. Ber. oberhess. Gesell. Nat. u. Heilk., Giessen, n. ser., Natiirw. Abt. i. 



1904-1906, pp. 43-85. 



(7) VoGELER and Thiele. Review by Kissel in Iter. Sci. Paris, 48 (1910), No. 14, 



pp. 438-439. 



(8) DASSONNTiJyE. Revue ge'ne'rale de Botanique, 10, 1898. 



(9) Kissel. Loc cil. 



