THE EVIDENCE FROM DEGENERATION. 



345 



of the living being and its surroundings applied to the newer concep- 

 tions of life and nature which modern biology has revealed. The 

 living thing is not a stable unit in its universe, however wide or 

 narrow that sphere may be. On the contrary, it exists in a condition 

 of continual war, if one may so put it, between its own innate powers 

 of life and action, of living and being, and the physical powers and 

 conditions outside. This much is now accepted by all scientists. 

 Differences of opinion certainly exist as to the share which the 

 internal constitution of the living being plays in the drama of life 

 and progress. It seems, however, most reasonable to conclude that 

 two parties exist to this, as to every other bargain ; and regarding the 



FIG. 243. BRACHIOPODS. 



FIG. 244. KING-CRAB. 



animal or plant as plastic in its nature, we may assume such plasticity 

 to be modified on the one hand by outside forces, and on the other 

 by internal actions proper to the organism as a living thing. 

 Examples of such tendencies of life are freely scattered everywhere 

 in nature's domain. For instance, we know of many organisms which 

 have continued from the remotest ages to the present time, without 

 manifest change of form or life, and which appear before us to-day, 

 the living counterparts of their fossilised representatives of the 

 Chalk or it may be of Silurian or Cambrian times. The lampshells 

 (Terebratula) of the Chalk exist in our own seas with well-nigh 

 inappreciable differences. The Lingula or Lingulella (Fig. 243, a), 

 another genus of these animals, has persisted from the Cambrian age 



