410 LAMARCK, HIS LIFE AND WORK 
Karl Jordan * proposes the term “‘ mechanical selec- 
tion’’ to account for them, but he points out that 
this factor can only work on variations produced by 
other factors. Certain cases, as the similar variation 
in the same locality of two species of different fam- 
ilies, but with the same wing pattern, tell in favor 
of the direct action of the local surroundings on the 
markings of the wings. 
In the same direction are the essays of Schroeder + 
on the markings of caterpillars, which he ascribes to 
the colors of the surroundings; of Fischer t on the 
transmutations of butterflies as the result of changes 
of temperature, and also Dormeister’s § earlier paper. 
Steinach | attributes the color of the lower verte- 
brates to the direct influence of the light on the pig- 
ment cells, as does Biedermann. 4 
In his address on evolution and the factors of 
evolution, Professor A. Giard ** has given due credit 
to Lamarck’ as ~~ the, creator of transformism,- and 
to the position to be assigned to natural selection as 
a secondary factor. He quotes at length Lamarck’s 
*“*On Mechanical Selection and Other Problems.”  MVovttates 
Zoologice, iii. Tring, 1896. 
+ Entwicklung der Raupenzeichnung und Abhaingigkeit der letzeren 
von der Farbe der Umgebung, 1894. 
t Zransmutation der Schinetterlinge infolze Temperatur-verinder- 
ungen, 1895. 
S Ueber den Einfluss der Temperatur bet der Erzeugung der 
Schmetierlings-vartetiten, 1880. 
|| Ueber Farbenwechsel bet niederen Wirbelthieren, bedingt durch 
directe Wirkung des Lichts auf die Pigmentzellen. Centralblatt fiir 
Phystologie, 1891, v., p. 326. 
q Ueber den Farbenwechsel der Frésche. Pfliiger’s Archiv fir 
Physiologie, 1892, li., p. 455. 
** Zecon a’ Ouverture du Cours de l’ Evolution des Etres organisés, 
Paris, 1888, and ‘‘ Les Facteurs de l’Evolution,” Revue Scientifique, 
November 23, 1889. 
