CHAPTER XXIV. 



GENERAL CONSIDERATIONS'. CONCLUSION. 



Test of True Theory. Explanation of present existence of Low Or- 

 ganisms. Limits of Ephemeromorphism uncertain. Difficulties 

 concerning some Lower Organisms. Comparative fixity of Higher 

 Types. Nature of Foraminifera. Apparent Persistence of certain 

 Forms through long Ages. Another Explanation of same Facts. 

 Professor Huxley on 'Persistent Types.' Different Explanation 

 of Facts. Similarity of independent Forms might be expected. 

 Demands upon Time required by Mr. Darwin's Hypothesis. Sir 

 Wm. Thomson's Views. These more in accordance with New 

 Theories. Interpretation of Palaeontological Records. Similarity 

 amongst Lower, and dissimilarity amongst Higher Organisms in 

 different Ages. No Continuous Progression. Imperfections of the 

 Geological Record. Mode of Origin of Human Race. Questions 

 concerning Superiority of Type. The Insect and the Fish. Stress 

 laid upon Complexity of Structure rather than of Function. Sub- 

 divisions of Vertebrate Type. Evidences of Divergence amongst 

 them. Many of them not necessary Precursors of Man's Appear- 

 ance. Increase in Development of Brain. First Social Habits. 

 Mr. Wallace on results of Comparative Stability of Man's External 

 Form with Progressive Development of Brain. Prejudices con- 

 cerning Origin of Human Race. Their Childish Nature. Future 

 Prospects. Conclusions. 



AS Mr. Wallace has very truly said, c There is no 

 more convincing proof of the truth of a com- 

 prehensive theory than its power of absorbing new 

 facts, and its capability of interpreting phenomena 



