"DIE STAMME DES THIERREICHS " 63 



Neumayr establishes, in the first place, the in- 

 separable connection of palaeontology with zoology. 

 The study of fossil animals is only the more delicate 

 in that the solid parts alone bones, teeth, and 

 shells have been preserved in the act of fossiliza- 

 tion ; entirely soft animals have generally left no 

 traces of their presence. In addition, the erosion of 

 the littoral deposits has too often caused to vanish 

 the collection of beings which dwelt on the shores of 

 the early seas, faunas necessarily more rich and 

 varied than the faunas of deep waters. Conse- 

 quently the inventory of fossil animals is far from 

 complete compared with that of living animals ; 

 in one of the geological periods with which he was 

 best acquainted that is, the great Jurassic period 

 Neumayr estimates the probable number of species 

 at 750,000, of which we as yet know hardly 10,000 

 a proportion of two per cent. The palaeontologist 

 must therefore expect numerous gaps when he en- 

 deavours to reconstitute the series of vanished 

 forms. We here again meet with, we see, the 

 pleading of Darwin as to the insufficiency of palse- 

 ontological documents on this point, but this time 

 with more exact facts. 



Neumayr also devotes a good portion of his 

 introduction to the study of transformism con- 

 sidered in existing nature. The most important 

 question, the one which overshadows all others in 

 the matter of evolution, is that of the variability of 

 species, the constant starting-point of all trans- 

 formist theories since Lamarck. Among living 

 forms this variability is far from general, which 

 explains the belief of many naturalists of high 



