oe 
230 [Dee. 15, 
Jope. ] 
In the present state of biological science, essays like the present can 
only be tentative in so far as they treat of the laws of evolution. Never- 
theless the present time is preéminently one of generalization in this 
field, and properly so. Facts have been accumulating for a long period, 
and are now sufficiently numerous to yield important results, under proper 
classification and induction. Darwin led the way in this work, and 
the development hypothesis is regarded as demonstrated by most biolo- 
gists. The discussion of the laws of its progress involves a multitude of 
subordinate hypotheses. In the following essay, these are arranged 
under five prominent heads, viz: 1, The law of Acceleration and Retarda- 
tion; 2. The law of Repetitive Addition; 8. The law of Use and Effort; 
4. The law of Grade Influence; 5. The law of Intelligent Selection. Of 
these, the first and second are regarded by the author as demonstrated, 
the third and fourth as only reduced toa partial demonstration, while 
the fifth is a consequence of the third, and stands or falls with it. 
The discussion of this subject divides itself into two parts, viz: a con- 
sideration of the proof that evolution of organic types or descent with 
modification has taken place; and secondly, the investigation of the laws 
in accordance with which this development has progressed. As the latter 
involves the use of the evidence included in the former, I will not de- 
vote a special chapter to the proof for evolution. 
The influences and forces which have operated to produce the type 
structures of the animal kingdom have been plainly of two kinds; 1. 
Originative, 2. Directive. The prime importance of the former is obvi- 
ous; that the latter is only secondary in the order of time or succession, 
is evident from the fact that it controls the preservation or destruction of 
the results or creations of the first, and thus furnishes the bases of the 
exhibitions of the originative forces in the production of the successive 
generations of living beings. 
Wallace and Darwin have propounded as the cause of modifica- 
tion in descent their law of natural selection. This law has been ep- 
itomized by Spencer as the ‘‘survival of the fittest.”” This neat ex- 
pression no doubt covers the case, but it leaves the origin of the fittest en- 
tirely untouched. Darwin assumes a ‘‘tendency to variation”’ in nature, 
and it is plainly necessary to do this, in order that materials for the exer- 
cise of a selection should exist. Darwin and Wallace’s law is, then, only 
restrictive, directive, conservative, or destructive of something already 
created. I propose then to seek for the originative laws by which these 
subjects are furnished—in other words, for the causes of the origin of the 
fittest. 
It has seemed to the author so clear from the first as to require no dem- 
onstration, that Natural Selection includes no actively progressive principle 
whatever; that it must first wait for the development of variation, and 
then after securing the survival of the best, wait again for the best to pro- 
ject its own variations for selection. Jn the question as to whether the 
latter are any better or worse than the characters of the parent, natural 
selection in no wise concerns itself, 
sell 
