DR. DRAPER'S LECTURE ON EVOLUTION. 177 



After a very long and exhaustive survey of the plants and animals 

 of his own locality, and of all that the power and favor of Alexander 

 the Great enabled him to inspect, this is the result to which Aristotle, 

 the prince of ancient Greek naturalists, came. In the eighth book of 

 his " History of Animals," when speaking of the chain of living things, 

 he says : " Nature passes so gradually from inanimate to animate 

 things, that from their continuity the boundary between them is in- 

 distinct. The race of plants succeeds immediately that of inanimate 

 objects, and these differ from each other in the proportion of life in 

 which they participate ; for, compared with minerals, plants appear 

 to possess life, though when compared with animals they appear in- 

 animate. The change from plants to animals is gradual ; a person 

 might question to which of these classes some marine objects belong." 

 Aristotle referred the primitive organisms to spontaneous generation. 



In the Museum of Alexandria the views of Aristotle were greatly 

 expanded. There it was discovered that animated Nature presents 

 something more than a mere connection ; that each link of Aristotle's 

 chain, if such a phraseology must be continued, was the descendant of 

 its predecessor, the progenitor of its successor. The idea now lost its 

 mechanical aspect and assumed a physiological one. 



We remark an important extension of this view after the conquest 

 of Alexandria by the Arabians. If we compare the order of affiliation 

 in successive points, it obviously presents a new fact progress ; and 

 not progress only, but progress from the imperfect to the more per- 

 fect. This view included lifeless as well as living Nature. A practi- 

 cal application of it arose, to which the designation Alchemy was 

 given. There is an unceasing progression, in which all things take 

 part, to a better and nobler state. In this slow development Nature 

 has no need to hasten ; she has eternity to work in. Thus, in the min- 

 eral world, base and unworthy metals, such as lead and tin, are slowly 

 on their way to perfection. They reach their goal on turning into 

 gold. It is, then, for us to ascertain the favoring conditions, and, by 

 imitating or increasing them, to hasten on the work. 



The literature of those ages is pervaded with the idea of the 

 mutability of everything a proneness of all living beings to suffer 

 transmutation, with changes in the environment, or in the physical 

 conditions to which they are exposed ; and thus arises a slow but con- 

 tinuous procession, in the unceasing lapse of time, to the beautiful and 

 good. We meet with this in both the serious philosophical works 

 of the Mohammedans, and in their lighter compositions of romance. 

 They wrote books on the production of animals both by generation 

 and putrefaction. They thought that in the germ there exists a latent 

 force tending to evolve it. Ibn Roschd says : " There are, as respects 

 the origin of living beings, two opposite theories. Some explain 

 their existence by development, others by creation. The latter is the 

 opinion of the Christians, as well as of our Motacallemin." Abubacer 



VOL. XII. 12 



