March, 1922] 
TELLEFSEN RELATION OF AGE TO SIZE 
Cincinnati for suggesting the problem and for his kindly and patient direc- 
tion of the work. 
BIBLIOGRAPHY 
Batten, Lily. 1918. Observations on tiie ecology of Epilohium hirsutum. Jour. Ecol. 6: 
161-177. 
Benedict, H. M. 191 5. Senile changes in leaves of Vitis vulpina L. and certain other plants. 
Cornell Univ. Agr. Exp. Sta. Memoir 7. 
Brotherton, W., and Bartlett, H. H. 191 8. Cell measurement as an aid in the analysis of 
quantitative variation. Amer. Jour. Bot. 5: 192-206. 
Curtis, O. F. 191 8. Stimulation of root growth in cuttings by treatment with chemical 
compounds. Cornell Univ. Agr. Exp. Sta. Memoir 14. 
Ensign, M. R. 1919. Venation and senescence of polyembryonic Citrus plants. Amer. 
Jour. Bot. 6: 311-329. 
Hayden, Ada. 1919. The ecologic subterranean anatoni}' of some plants of a prairie 
province in central Iowa. Amer. Jour. Bot. 6: 87-105. 
Lamb, G. N. 1915. Willows: Their growth, use and importance. U. S. Dept. Agr. Con- 
trib. For. Serv. Bull. 316. 
Norris, F. D. M. 1913. Production of air passages in the root of Zea Mays by variation 
of the culture media. Ann. Rep. and Proc. Bristol Naturalists' Soc. IV, 3: 134-136, 
Scott, D. H., and Wager, H. 1888. On the floating-roots of Seshania aculeata Pers. Annals 
of Bot. i: 307-314. 
