152 THE AMERICAN NATURALIST, 
character of the curves and the position of their means and 
modes likewise change continuously. 
I wish to express my thanks to Prof. W. L. Tairas for his 
kindly interest and helpful suggestion during the prosecution 
of these studies, and also for the revision of the manuscript. 
YELLOW SPRINGS, OHIO, " 
June 25, 19or. 
BIBLIOGRAPHY. 
BURKILL, I. H. 
1895. On Some Variations in the Number of Stamens and Carpels. 
Linnean Society Journal of Botany. Vol. xxxi, pp. 216—245. 
DAVENPORT, C. B. 
1899. Statistical Methods with Special Reference to Biological Varia- 
tion. New York, John Wiley & Sons. 59 pp., 10 tables, 28 figs. 
LUCAS, RF. €. 
1898. Variation in the Number of Ray-Flowers in the White Daisy. 
Amer. Nat. Vol. xxxii, No. 379, pp. 509-511. 2 figs. 
Lupwic, F. 
895. Ueber Variationskurven und Variationsflachen der Pflanzen. 
Botanisches Centralblatt. Bd. lxiv, pp. 1-8, 33-41, 65-72, 
97-105. 2 Tafeln 
Lupwic, F. 
1896. "Weiteres über Fibonaccicurven. Botanisches Centralblatt. 
Bd. Ixviii, pp. 1-8. t Taf. 
Lupwic, F. 
1896. Eine fünfgipfelige Variationscurve. Berichte deutsch. Bot. Ges. 
Bd. xiv, pp. 204-207. 1 fi 
Lupwic, F. 
1898. Die pflanzlichen Variationscurven und die Gauss'sche Wahr- 
scheinlichkeitscurve. Botanisches Centralblatt. Bd. Ixxiii, 
pp. 241—250, 289-296, 343-349, 374-379. 1 Doppeltaf. 
Lupwie, F. 
Ueber Variationscurven. Botanisches Centralblatt. Bd. Ixxv, 
PP- 97-107, 178—183. 1 Doppeltaf 
Lupwic, F. 
1900. Ueber Variationspolygone und Wahrscheinlichkeitscurven. Bei- 
hefte zum botanischen Centralblatt. Bd. ix, Beiheft 2, pp. 89- 
Ht 1 8 
STRONG, R. M. 
1901. A Fen enin Study of Variation in the Smaller North-American 
hrikes. Amer. Nat. Vol. xxxv, No. 412 (April, 1901), 
»- 271-298. 8 figs. 
