92 THEOLOGIANS AND NATURAL PHILOSOPHERS. 



cause does not, however, in such cases rise to a regular form, but 

 only in the latent process towards such a form, for he who is ac- 

 quainted with the paths of Nature will more readily observe their 

 deviations, and vice versa, he who has learnt her deviations will be 

 able more accurately to describe her paths." 



Having thus spoken of deviations or variations, 

 and of the necessity of understanding the normal 

 type in order to detect the variation, also of the de- 

 sirability of studying the cause of the variation, 

 Bacon proceeds to point out that it is possible for 

 man to produce variations experimentally, and shows 

 that living objects are well adapted to experimental 

 work : — 



" They differ again from singular instances, by being much more 

 apt for practice and the operative branch. For it would be very 

 difficult to generate new species, but less so to vary known species, 

 and thus produce many rare and unusual results. The passage 

 from the miracles of Nature to those of Art is easy ; for if Nature 

 be once seized in her variations and the cause be manifest, it will 

 be easy to lead her by Art to such variation as she was first led 

 to by chance ; and not only to that, but others, since deviations 

 on the one side lead and open the way to others in every direction." 



In the above passage Bacon points out that in arti- 

 ficial selection we take advantage of the chance varia- 

 tions of Nature, and accumulate them. In the next 

 passage he points out the presence of transitional 

 fornis in Nature between two types (Section 30.) : 



" In the ninth rank of prerogative instances we will place bor- 

 dering instances, which we are also wont to term participants. They 

 are such as exhibit those species of bodies which appear to be 

 composed of two species, or to be the rudiments between one and 



