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SCIENCE 



[N. S. Vol. XXVI. No. 657 



out for the land when in its change it 

 passed the optimum. We shall, I think, 

 find that this latter hypothesis is the more 

 likely to be true. But it does not seem 

 that we can readily dismiss the second 

 from consideration. 



There are other weaknesses in Quinton's 

 theory, one of which we may now mention, 

 leaving the rest until later. That is that 

 his theory does not take in plants, and 

 their circulating medium. 



The lower plants and animals are not 

 far apart, and we can hardly suppose a 

 different origin. Yet plants must have 

 existed before animals, just as herbivora 

 must have existed before carnivora, and 

 the eat presupposes the existence of the 

 mouse. Plants as well as animals have 

 protoplasm or living matter, dead matter, 

 and secretions and a vital fluid or sap. 

 But the sap is of much low^er concentra- 

 tion and different composition from ani- 

 mals. Quinton's hypothesis needs to be 

 supplemented by some explanation of the 

 relations between plants and animals. 



We are then prepared to consider Quin- 

 ton's valuable law with an open mind, and 

 see how far its inferences as to the sur- 

 roundings of early life agree with those of 

 dynamic and historical geology. 



1. Quinton infers that the early ocean 

 had a temperature not far from 44° C. 

 (111° F.) which is not far from the hottest 

 blood temperature of birds. It is certainly 

 a remarkable fact that from the tropics 

 to the poles, in spite of the tendency of 

 the environment in arctic and temperate 

 climes, the blood heat of the more vigorous 

 and active animals in the various orders of 

 vertebrates falls not over 10° below this 

 temperature. 



Quinton's explanation is not the only 

 one, however. The other is that the proc- 

 esses of oxidation and combustion, which 

 furnish the energy for the bodily activity, 



and the supply of heat to keep the body 

 warm, raise the same to a heat which is 

 best for cell activity, or perhaps even to 

 the temperature which can be stood with- 

 out serious damage. 



A careful investigation of blood tem- 

 peratures and bodily activity, which are in 

 some ways correlated, might be very signif- 

 icant. 



Geologically we can not speak with 

 as much assurance as we might have be- 

 fore radium and the newer theories of 

 cosmogony had undermined all certain- 

 ties. Glacial periods indeed are reported 

 upon strong evidence from early geological 

 times. Nevertheless, whether we believe in 

 a gradually refrigerating climate, on a 

 cooling globe, warmed by a dying sun, or 

 not, the former wide extent of corals and 

 ferns toward the north pole is undoubted. 

 Van't Hoff finds a hot climate indicated 

 by the Stassfurt salt deposits. We must 

 therefore allow the possibility, and I think 

 most of us would say probability, of a 

 much warmer ocean at least at times in the 

 past, than at present. We may then 

 imagine, and it was to me an illuminating 

 thought, that the early "fish" were not 

 cold-blooded animals at all, but active 

 warm-blooded creatures whose blood tem- 

 perature was that of the warm ocean 

 around, which has been retained by the 

 higher of their descendants. It seems 

 probable that such a warmer ocean would 

 accelerate all organic activity, including 

 evolution. 



Upon the basis of a cooling environment 

 Quinton builds an ingenious genealogical 

 tree. He imagines the secular cooling of 

 the surroundings as depressing also the 

 body temperature of all except a few forms 

 which make special modifications to keep it 

 up. Then a farther fall will lower all 

 except a fraction of the first fraction, who 

 have assumed such farther modification as 



