466 Recent Literature. [May 
views of others who have been associated with him in similar 
1. Darwin’s law of natural selection, or the survival of the 
fittest, is secondary to the question of the origin of the fittest; 
îe., variations. According to Darwin, organisms have an inhe- 
rent tendency to vary, and variations are fortuitous. 
2. Professor Cope denies any inherent tendency to vary. There 
are no tendencies except growth and heredity. 
3. Variations are due to 
(2) Physical and chemical effects of environment. 
(6) Use and disuse. The effect of use and disuse in the indi- 
vidual is plainly. seen, and can be shown in successive generations 
by palzontological evidence. 
c£) Consciousness implying effort producing motion. The 
object of the effort is to satisfy hunger or to give pleasure; the 
result is variation in the parts used. Sensibility is therefore an 
important factor in producing variation. 
e results of physical selection and of use and disuse are 
constant, those of natural selection more or less fluctuating. 
5. Separate groups may vary independently in the same or 
‘similar directions owing to the action of similar conditions. 
6. These features of variation appear usually in adults. But 
by acceleration they are inherited in younger stages. Embry- 
ology thus becomes crowded and many useless stages are 
skipped. By retardation variations may be inherited by later 
stages. 
Some of Professor Cope’s personal views most worthy of note 
are these: 
course room for great difference of opinion. The most important 
conclusions are those relating to physical selection and the effect 
