BIOGRAPHICAL SKETCH Ixvil 
“T venture to assert that variation is sometimes orderly, and at 
other times rather disorderly, and that the one is just as free from 
teleology as the other. In our aversion to the old teleology, so 
effectually banished from science by Darwin, we should not for- 
get that the world is full of order, the organic no less than the 
inorganic. Indeed what is the whole development of an organism 
if not strictly and marvelously orderly? Is not every stage, from 
the primordial germ onward, and the whole sequence of stages, 
rigidly orthogenetic? If variations are deviations in the direc- 
tions of the developmental processes, what wonder is there if in 
some directions there is less resistance to variation than in others? 
What wonder if the organism is so balanced as to permit of both 
unifarious and multifarious variations? If a developmental 
process may run on throughout life (e.g., the lifelong multiplica- 
tion of the surface-pores of the lateral-line system in Amia), 
what wonder if we find a whole species gravitating slowly in one or 
a few directions? And if we find large groups of ‘species all 
affected by a like variation, moving in the same general direction, 
are we compelled to regard such ‘a definite variation-tendency’ 
as teleological, and hence out of the pale of science? If a designer 
sets limits to variation in order to reach a definite end, the direc- 
tion of events is teleological; but if organization and the laws of 
development exclude some lines of variation and favor others, 
there is certainly nothing supernatural in this, and nothing which 
in incompatible with natural selection. Natural selection may 
enter at any stage of orthogenetic variation, preserve and modify 
in various directions the results over which it may have had no 
previous control.” 
The particular evidence in favor of orthogenesis on which 
Whitman rested his case is found in the origin of the bars on the 
wings of the wild pigeons and on the wings of many domesticated 
birds. 
“The rock pigeons (Columba livia) present two very distinct 
color-patterns; one of which consists of black checkers uniformly 
distributed to the feathers of the wing and the back, the other of 
two black wing-bars on a slate-gray ground. These two patterns 
may be seen in almost any flock of domestic pigeons. 
