NATURAL HISTORY OF CREATION. 167 



cereale is the crop reaped where the avena saliva, a 

 recognised diiferent genus, was sown. Now it will not 

 satisfy a strict inquirer to be told that the seeds of the 

 rye were latent in the ground, and only superseded the 

 dead product of the oats ; for if any such fact were in the 

 case, why should the usurping grain be always rye ? 

 Perhaps those curious facts which have been stated with 

 regard to forests of one kind of trees, when burnt down, 

 being succeeded (without planting) by other kinds, may 

 yet be found most explicable, as this is, upon the 

 hypothesis of a progression of species which takes place 

 under certain favouring conditions, now apparently of 

 comparatively rare occurrence. The case of the oats is 

 the more valuable, as bearing upon the suggestion as to 

 a protraction of the gestation at a particular part of its 

 course. Here, the generative process is, by the simple 

 mode of cropping down, kej^t up for a whole year beyond 

 its usual term. The type is thus allowed to advance, 

 and what was oats becomes rye. 



The idea, then, which I form of the progress of organic 

 life upon the globe — and the hypothesis is ajDplicable to 

 all similar theatres of vital being — is, that the simplest and 

 most jyt'iniitive tf/jje, under a laio to lohich that of like- 

 2)roduction is sichordinate, gave birth to the type next above 

 it, that this again produced the next higher, and so on to 

 the very highest, the stages of advance being in all cases 

 very small — namely, from one species only to another; 

 so that the phenomenon has always been of a simple and 

 modest character. Whether the whole of any species 

 was at once translated forward, or only a few parents 

 were employed to give birth to the new type, must remain 

 undetermined ; but, supposing that the former was the 

 case, we must presume that the moves along the line or 

 lines were simultaneous, so that the place vacated by one 



