194 



THE AMEfnCAN MUSEUM JOURNAL 



ergv will ])r<)ve to he a stej) in the i-iglit 

 direction."" 



The proljlem leads from a piii'cly in- 

 organic world to a world with simple 

 life forms, and from such a simply 

 ])eopled world to one witli all the amaz- 

 ing richiic-> and di\crsity of the living 

 present. Asironomy and geology fui-- 

 nish ns with a elear and simple conce])- 

 tion of the evolution of the stellar uni- 

 verse and of the earth itself, demon- 

 strahle in many of its features. Do 

 these pi'oces<es of evolution lead to the 

 origin of life foj'ms. oi' with the origin 

 1)1' life foi-nis have we a manifestation 

 of some new princijjley If life forms 

 originated conformahly with stellar and 

 woi'ld forms, was it a gradual or a sud- 

 den pi-ocess? Has the farther evolu- 

 tion of oi'gnnisms ])i-ocee(led according 

 to definite ])hysiological laws of devel- 

 opment, or has it heen gaiided \)y chance 

 as conceived l)y Darwin? 



Whatever the difficulty of these ques- 

 tions, however inconceivable it may ap- 

 pear that demonstrable answers can bo 

 furnished, or that the almost infinitely 

 various detaile(l ]n'oblems on which the 

 solution of the wdiole rests should he 

 workt'(l out. it is impossible that the 

 attem])t should not be made to work out 

 a single causal nexus of events. A great 

 merit of the ])resent work is that it 

 evades no difficulty, hut clearly sets 

 forth the prol)]ems to be solved, and 

 utilizes all the resources of the various 

 evolutionary sciences to furnish sug- 

 gestions and ])ro])ose hypotheses. 



That evolution is due to the actions, 

 ]-eactions. anl interactions of the forms 

 of matter and energy of the ])rimitive 

 world. M'hich occur everywhere in the 

 universe, is the guiding idea. These 

 constitute four groups in the actual 

 evolutionaiw ])rocess. namel_y, the inor- 

 gaiuc envii'onment. the organism, the 

 heredity-germ, and the life environ- 

 ment — hence the term tetraplasy— and 

 selection is oi^erating constantly at 

 every stage of the process. 



The chapters deal with the prepara- 



tion of the eai'tli for life; the sun and 

 the ])hysicoclienncal origins of life: en- 

 ei'gy evolution of bacteria, algs, and 

 plants ; the origins of animal life and 

 the e\<)lution of the invertebrates; the 

 visil)le and invisible evolution of the 

 vertebrates ; evolution of body form in 

 tile fishes and amphibians; form evolu- 

 tion of the reptiles and Ijirds; evolution 

 of the mammals. 



The aspect of adaptation runs all 

 through the treatment. To begin with. 

 I'rofessor Osborn takes over with ap- 

 ])roval Henderson's conceptions of the 

 fitness of the life elements and of the 

 inorganic environment; he finds fitness 

 in the nature of the colloidal system of 

 ])rotoplasni "])eculiarly favorable to . . . 

 tlie free interchange of physicochemical 

 enei'gies."" He emphasizes the adapta- 

 tion of the organism to the environ- 

 ment, and the adai)tation of the in- 

 ternal correlations of the organism 

 through internal secretions, enzymes 

 and the nervous system. Special as- 

 pects of adaptation are dealt with in 

 the laws of form evolution with refer- 

 ence to locomotion, offense and defense, 

 and reproduction, as illustrated in the 

 laws of convergence and of adaptive 

 radiation. The inde})endently adaptive 

 aspects of different organs, as they radi- 

 ate in evolution in correlation with 

 \ai'ie(l en\ ii'onments, "is fatal to any 

 form of belief in an internal perfecting 

 tendency which may drive animal evo- 

 lution in any particular direction or 

 directions. Finally, it is fatal to Dar- 

 win's original natural-selection hy- 

 ])othesis. which would imply that the 

 teeth, limlx. and feet are varying for- 

 tuitously rather than evolving under 

 certain definite although still unknown 

 laws." 



The study of evolution runs in two 

 closely related parallel lines, the visible 

 line of the body or soma and the in- 

 visil)le line of the germ or "heredity- 

 chromatin." The author states the 

 Damarckian hypothesis that somatic 

 evolution precedes and controls germ- 



