386 LAMAKCK, HIS LIFE AND WORK 
Selection. The one is so completely and adrectly 
proved by the other, and established by mechanical 
causes, that there remains nothing to be desired. 
The laws of Jzheritance and Adaptation are univer- 
sally acknowledged physzological facts, the former 
traceable to propagation, the latter to the xztrztionu 
of organisms. On the other hand, the s/ruggle for 
existence is a biological fact, which with mathemati- 
cal necessity follows from the general disproportion 
between the average number of organic individuals 
and the numerical excess of their germs.’’ * 
A number of American naturalists at about the 
same date, as the result of studies in different direc- 
tions, unbiassed by a too firm belief in the efficacy 
of natural selection, and relying on the inductive 
method alone, worked away at the evidence in favor 
of the primary factors of evolution along Lamarckian 
lines, though quite independently, for at first neither 
Hyatt nor Cope had read Lamarck’s writings. 
In 1866 Professor A. Hyatt published the first of 
a series of classic memoirs on the genetic relations 
of the fossil cephalopods. His labors, so rich in 
results, have now been carried on for forty years, 
and are supplemented by careful, prolonged work on 
the sponges, on the tertiary shells of Steinheim, and 
on the land shells of the Hawaiian Islands. 
His first paper was on the parallelism between the 
different stages of life in the individual and those of 
the ammonites, carrying out D’Orbigny’s discovery 
of embryonic, youthful, adult, and old-age stages 
in ammonites,t and showing that these forms are 
* Schépfungsgeschichte, 1868. The History of Creation, New 
York; *iseps 355: 
+ Alcide d’Orbigny, Paléontologie frangaise, Paris, 1840-59. 
