216 PROGRESSIVE DEVELOPMENT. 



isting where they are not necessary, must, it is thought, be 

 regarded as blemishes and blunders, on the supposition that 

 the beings who possess them were created independently and 

 by special exertion ; but they are considered as precisely what 

 might have been expected on the supposition that creation has 

 proceeded through her various ramifications and transitional 

 stages, according to the energizing and directing influence of a 

 uniform law of development. 



In further illustration and support of the theory of progres- 

 sive development, the writer quotes the following startling 

 passage from Fletcher's Rudiments of Physiology, in which it 

 is shown that the general forms, and the order of succession, 

 of the developments in the animal kingdom, are represented 

 by the general forms, and the order of succession, of the de- 

 velopments of the human foetus. "It is a fact" (says Dr. 

 Fletcher), " of the highest interest and moment that, as the 

 brain of every tribe of animals appears to pass, during its de- 

 velopment, in succession through the types of all those below 

 it, so the brain of man passes through the types of those of 

 every tribe in the creation. It represents, accordingly, before 

 the second month of uterogestation, that of an avertebrated 

 animal ; at the second month, that of an osseous fish ; at the 

 third, that of a turtle ; at the fourth, that of a bird ; at the 

 fifth, that of one of the rodentia ; at the sixth, that of one of 

 the ruminantia ; at the seventh, that of one of the digitagrada ; 

 at the eighth, that of one of the quadrumana ; till, at length, at 

 the ninth, it compasses the brain of man. It is hardly neces- 

 sary to say," continues the writer, " that all this is only an 

 approximation to the truth ; since neither is the brain of all 

 osseous fishes, of all turtles, of all birds, nor of all the species 

 of any of the above order of mammals, by any means precisely 

 the same ; nor does the brain of the human foetus at any time 



