188 K. E. vox BAER. PHILOSOPHICAL FRAGMENTS. 



children and grandchildren for a few myriads of years, and at 

 last who can be astonished that the fins become feet ? It is still 

 more natural that the fish in the meadow, finding no water, 

 should gape after air, thereby, in a like period of time, deve- 

 loping lungs ; the only difficulty being that in the meanwhile a 

 few generations must manage to do without breathing at all. 

 The long neck of the heron arose from a habit its ancestors ac- 

 quired of stretching out their necks for the purpose of catching 

 fish. The young ones in consequence came into the world with 

 their necks something the longer, and cultivated the same trick, 

 transmitting to their posterity still longer necks, whence w^e 

 may fairly expect, that when the world is getting very old, the 

 herons' necks will be past measuring altogether. 



An immediate consequence of the assumption of this idea as 

 a natural law was, that a view^ which had once been very gene- 

 ral, but had subsequently been pretty generally given up — that 

 of the universal progression of the different forms of animals — 

 gradually got footing again ; and though not often asserted in 

 80 many words, nay, perhaps unconsciously to naturalists them- 

 selves, it became admitted in discussions concerning animal 

 forms. It must be confessed that the natural law^ being as- 

 sumed, logical consequence required the admission of the view 

 in question. There was then only one road of metamorphosis, 

 that of further development, either attained in one individual 

 {individual metamorphosis), or through the different animal forms 

 {the metamorphosis of the animal kingdom) ; and disease was to 

 be considered as a retrogressive metamorphosis, because univer- 

 sal metamorphosis, like a railroad, allows motion backwards or 

 forwards, but not to one side. 



From such applications, opposed at once to unprejudiced in- 

 vestigation and to exact knowledge, the more cautious indeed, 

 and before all that advocate of the principle through whose name 

 it attained the w idest assent, carefully abstained ; but it cannot 

 be denied that they were the logical consequences of the law, 

 and thence a sufficient ground of distrust*. But the attacks of 



* It did not appear fitting here to give a detailed account of this theory, 

 for the purpose of attempting to refute it. Since a certain contradiction ap- 

 peared perceptible enough in Nature, it has been carried out b}' different men 

 very differently. Those who were best provided with special knowledge were 



