386 LAMARCK, HIS LIFE AND WORK 



Selection. The one is so completely and directly 

 proved by the other, and established by mechanical 

 causes, that there remains nothing to be desired. 

 The laws of Inheritance and Adaptation are univer- 

 sally acknowledged physiological facts, the former 

 traceable to propagation, the latter to the nutrition 

 of organisms. On the other hand, the struggle 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 



* Schdpfungsgeschichte, 1868. The History of Creation, New 

 York, ii., p. 355. 



f Alcide d'Orbigny, PaUontologie franfaise, Paris, 1840-59. 



