THE ORIGIN OF THE FORMS OF LIFE, 47 
fox, must we look for the wild progenitors of our dogs. Dar- 
win concluded that, as man had only utilized the materials Na- 
ture provided in forming his races of domestic animals, he had 
availed himself of the variations that arose spontaneously, and 
increased and fixed them by breeding those possessing the same 
variation together, so the like had occurred without his aid in 
nature among wild forms. 
Evolutionists are divided as to the origin of man himself; 
some, like Wallace, who are in accord with Darwin as to the 
Fie, 49.—Skeleton of hand or fore-foot of six mammals, I, man; II, dog; II, pig; IV, ox; 
V, tapir; VI, horse. 7, radius; u, ulna; a, scaphoid; b, semi-lunar; ¢, triquetrum (cunei- 
form) ; d, trapezium ; e, trapezoid i J, capitatum (unciform process) ; g, hamatum (unci- 
form bone) ; p. pisiform ; 1, thum 
; 2, digit; 8, middle finger; 4. ring-finger ; 5, little 
finger. (After Gegenbaur.) ee me 3 es 
origin of living forms in general, believe that the theory of 
natural selection does not suffice to account for the intellectual 
and moral nature of ‘man. Wallace believes that man’s body 
has been derived from lower forms, but that his higher nature 
is the result of some unknown law of accelerated development ; 
while Darwin, and those of his way of thinking, consider that 
man in his entire nature is but a grand development of powers 
existing in minor degree in the animals below him in the scale. 
Summary.—EKvery group of animals and plants tends to in- 
crease in numbers in a geometrical progression, and must, if 
unchecked, overrun the earth. Every variety of animals and 
plants imparts to its offspring a general resemblance to itself, 
but with minute variations from the original. The variations 
of offspring may be in any direction, and by accumulation 
