154 
BIOLOGY: A. J. LOTKA 
Proc. N. a. S. 
vides itself into two fields. The one, which might be termed the stoichiom- 
etry of evolution, deals with mass relations: the relative amounts of the 
different species of matter present, and the changes in these amounts; 
the kinetics of evolution. The second field of study is the dynamics or 
energetics of evolution, the scope of which is sufficiently indicated by these 
terms. It appeared desirable to lay the foundation of the first, as the more 
elementary, of these fields, before proceeding to a systematic exposition 
of the second. This is the plan which has been closely followed by the 
writer in the past, and which it is hoped to develop in greater completeness 
in the future. Material held in reserve, and relating to the dynamics 
of evolution, will then be brought forward in its proper place. The present 
issue of this advance sheet is prompted by a recent reading of Guilleminot's 
book, which, through a series of mishaps, has only recently come to the 
writer's hand. 
*Papers from the Department of Biometry and Vital Statistics, School of Hygiene 
and Public Health, Johns Hopkins University, No. 60. 
I These Proceedings, 8 p. 147. 
' Ostwald, W., Vorlesungen iiher Naturphilosophie, 1902, p. 328. 
' Sir Oliver Lodge, Life and Matter, 1906, p. 144. • 
* Ibid., pp. 148, 149; Nature, 67, p. 595; 68, p. 31. 
^ Guilleminot, H., La Matter e et la Vie, 1919, p. 121, et passim. 
^ This remark must be understood to apply only to that freedom which arises out of 
the incompleteness of the first and second law as determinants of the course of events. 
The writer does not here take sides, one way or another, in the controversies regarding 
free will, determinism, vitalism as distinguished from mechanistic conceptions, etc. 
^ Compare Lotka, A. J., /. Washington Acad. Sci., 2, 1912, p. 7 1; Guilleminot, H., 
loc. cit., p. 115; Johnstone, J., The Mechanism of Life, 1921, p. 49. 
» Lotka, A. J., Proc. Nat. Acad. Sci., 7, 1921, pp. 194, 196. 
9 Perrin, J., Traite de Chimie, 1903, vol. 1, pp. 142-143; Chowlson, O. T> . , Lehrhuch der 
Physik., 1905, vol. 3, p. 499; Scientia, 3, 1910, p. 51; Lotka, A. J., Science Progress, 14, 
1920, p. 406. 
10 For recent substantiation of some of the details of the presentation there given 
see Baly, E- C. C, Nature, vol. 109, 1922, p. 344. 
II D'Arcy Thompson {Growth and Form, 1917, p. 132) attributes the origination 
of this concept to Chodat, quoted by Monnier, A. {Publ. Inst. Bot. Univ. Geneve, 
(7) III, 1905. There seem to be, however, some earlier indications of the same 
thought. The following bibliography, which makes no pretense of completeness, is 
culled from works ready at hand: Errera, L., Revue de /' Universite de Bruxelles, 5, 
1899-1900. May issue; Ostwald, W., Vorlesungen iiher Naturphilosophie, 1902, pp. 342, 
et seq.; Bastian, H. C, The Nature and Origin of Living Matter, 1905, p. 46, et seq.; 
Robertson, T. B., Arch. Entwickelungsmechanik Org., 25, 1908, p. 581, 25, p. 108; Ost- 
wald, Wo., Die zeitlichen Eigenschaften der Entwickelungsvorgdnge, 1908; Hatai, S., 
Anat. Rec, 5, 1911, p. 373; Enriques, Biol. Centralbl., 1909, p. 337; Lotka, A. J., 
Z. physik. Chem., 72, 1910, p. 511; 80, 1912, p. 159; /. Phys. Chem., 14, 1910, p. 274; 
Proc. Nat. Acad. Sci., 6, 1920, p. 275; Pearl, R., Amer. J. Hygiene, 1, 1921, p. 592. 
12 Guilleminot, H., loc. cit., p. 118, 154, et passim. 
13 Lotka, A. J., Am. J. Sci., 24, 1907, p. 216; Ann. Naturphil., 1910, p. 74. 
