202 THE POPULAR SCIENCE MONTHLY. 



for organization, and therefore determined the course of organization ; 

 and, doing this, gave indelible traits to embryonic transformations and 

 to adult structures. 



Though mainly carried on after the inductive method, the argument 

 at the close of the foregoing section has verged towards the deductive. 

 Here let us follow for a space the deductive method pure and simple. 

 Doubtless in biology d priori reasoning is dangerous ; but there can 

 be no danger in considering whether its results coincide with those 

 reached by reasoning d posteriori. 



Biologists in general agree that in the present state of the world, 

 no such thing happens as the rise of a living creature out of non-living 

 matter. They do not deny, however, that at a remote period in the 

 past, when the temperature of the Earth's surface w T as much higher 

 than at present, and other physical conditions were unlike those we 

 know, inorganic matter, through successive complications, gave origin 

 to organic matter. So many substances once supposed to belong ex- 

 clusively to living bodies, have now been formed artificially, that men 

 of science scarcely question the conclusion that there are conditions 

 under which, by yet another step of composition, quaternary com- 

 pounds of lower types pass into those of highest types. That there 

 once took place gradual divergence of the organic from the inorganic, 

 is, indeed, a necessary implication of the hypothesis of Evolution, taken 

 as a whole ; and if we accept it as a whole, we must put to ourselves 

 the question What were the early stages of progress which followed, 

 after the most complex form of matter had arisen out of forms of mat- 

 ter a degree less complex ? 



At first, protoplasm could have had no proclivities to one or other 

 arrangement of parts ; unless, indeed, a purely mechanical proclivity 

 towards a spherical form when suspended in a liquid. At the outset 

 it must have been passive. In respect of its passivity, primitive or- 

 ganic matter must have been like inorganic matter. No such thing 

 as spontaneous variation could have occurred in it ; for variation 

 implies some habitual course of change from which it is a divergence, 

 and is therefore excluded where there is no habitual course of change. 

 In the absence of that cyclical series of metamorphoses which even 

 the simplest living thing now shows us, as a result of its inherited 

 constitution, there could be no point oVappiti for natural selection. 

 How, then, did organic evolution begin ? 



If a primitive mass of organic matter was like a mass of inorganic 

 matter in respect of its passivity, and differed only in respect of its 

 greater changeableness ; then we must infer that its first changes con- 

 formed to the same general law as do the changes of an inorganic 

 mass. The instability of the homogeneous is a universal principle. 

 In all cases the homogeneous tends to pass into the heterogeneous, and 

 the less heterogeneous into the more heterogeneous. In the primor- 



