274 SCIENTIFIC THOUGHT. 



semblance of apparent rest produced by very rapid rotary 

 motion. Rest and fixity of form seem only to exist 

 apparently or for transient moments in the history of 

 natural events ; and even the finished and recurring struc- 

 tures of living beings, which appear to our eyes to be 

 possessed of so much finality and sometimes of so much 

 finish, owe these qualities only to the comparatively short 

 space of time during which we are permitted to gaze 

 at them, and to our ignorance of the slow but endless 

 changes to which they are nevertheless subject. 



53. The period from 1800 to 1860 can be termed the 



The morpho- 

 logical morphological period of natural science. It succeeded 



the period of the simpler natural history, which had 

 been mainly occupied with classification and description 

 of specimens. During the morphological period the 

 knowledge of the existing things and forms of nature 

 was not only largely extended by excursions into distant 

 lands and periods of history, but forms were also studied 

 in situ, and the living things visited in their habitats. 

 A deeper knowledge of the connection and interdepend- 

 ence of natural things and events was thus gained, and 

 the relations and resemblances, the analogies and homo- 

 logies, of the various forms were impressed on the observer. 

 Besides all this, the microscope revealed the innermost 

 composition and the ultimate structural sameness of living 

 matter, adding moreover the knowledge of an enormous 

 creation which remains hidden to the unarmed eye of 

 the ordinary observer. The morphological view also took 

 note of the relatedness and apparent recurrence of definite 

 forms called types, of the so-called fixity of species and 

 the succeeding characteristic periods of creation, and 



