The Zoologist — February, 1869. 1531 



series, has an immortal spirit : it follows that at some point or other in 

 the chain of beings this great change must have taken place. This vital 

 question does not appear to have been considered by our Darwinian 

 philosophers, but in the ascending graduated scale it seems pretty clear 

 that the protozoon must be an inhabitant of earth, and man, in his 

 linal state, a denizen of heaven. 



There is some little appearance of discrepancy in the mode of 

 treating the changes that we have seen in progress. Mr. Darwin speaks 

 of "the innumerable species inhabiting the world as having been 

 modified so as to acquire that perfection of structure and coadaptation 

 which most justly excites our admiration;" but he goes on to say, 

 " Naturalists continually refer to external conditions, such as climate, 

 food, &c., as the only possible cause of variation. In one very limited 

 sense, as we shall hereafter see, this may be true ; but it is preposterous 

 to attribute to mere external conditions, the structure, for instance, of 

 the woodpecker, with its feet, tail, beak and tongue so admirably 

 adapted to catch insects under the bark of trees." Wilson Armistead, 

 who so fondly and lovingly dwells on the upward progress of the Negro, 

 attributes, on the other hand, all structural modifications to ex- 

 ternal causes, setting in array a multitude of instances, in which 

 animals are changed in form, colour, size and economy, by external 

 conditions of latitude and longitude, heat and cold, light and 

 darkness. Mr. Darwin modifies all this, and admits to the full 

 the difficulty of understanding how "a simple being or a simple 

 organ can be changed and perfected into a highly developed 

 being or an elaborately constructed organ;" but he devotes an 

 entire chapter to explain that the change does take place; and he 

 subsequently declares, as a matter established beyond all doubt, thaf 

 this evolving and improving process is an inherent principle of life, 

 and in no way dependent on externals or casualities, the effects of 

 which he also fairly and dispassionately considers. Near the close of 

 his original work, Mr. Darwin thus expresses himself: "As all the 

 living forms of life are the lineal descendants of those which lived long 

 before the Silurian epoch, we may feel certain that the ordinary succes- 

 sion by generation has never once been broken, and that no cataclysm 

 has desolated the whole world. Hence we may look with some con- 

 fidence to a secure future of equally inappreciable length. And as 

 natural selection works solely by and for the good of each being, all 

 corporeal and mental endowments will tend to progress towards per- 

 fection."—' Origin of Species,' p. 489. 



