Pike: The Utility of Death 



199 



organism is impaired and frequently 

 death results. 



HEREDITARY LIMITS 



The limitation of changes in the 

 central nervous system in all probability 

 sets a limit to man's achievements 

 during his lifetime. And in no case is 

 a sufficient amount of change possible 

 in the lifetime of any higher organism, 

 no matter how prolonged, to lead to the 

 development of new genera or species. 



It is man's nervous system which has 

 raised him above the animals, and on 

 which his progress for the future de- 

 pends.^ Limitation of change in this 

 system probably means a limitation of 

 personal achievement, and would mean 

 a limitation of the achievement of the 

 race if no progressive change through 

 the production of new individuals were 

 to occur. Changes of sufficient magni- 

 tude for purposes of organic evolution 

 can occur only through the cumulative 

 effects, persisting through many genera- 

 tions, of the small changes, always 

 toward something better if the race or 

 the species is to endure and take its 

 place in the hierarchy of organic life, 

 appearing in each successive generation 

 of new individuals. The immortality 

 of all individuals which have ever ap- 

 peared' upon the earth would have 

 resulted in an insufferable congestion 

 and a ferocity of the struggle for exist- 

 ence which would transcend anything 

 we now know. Ferocity does not seem 



to be now, nor to have been in the past, 

 the sole object of evolution. 



The development of the metazoan 

 body has led to the greater independence 

 of the organism and greatly increased 

 its efficiency. But the coordination of 

 all activity has led to the development 

 of a rigid physico-chemical and anatom- 

 ical basis in which change is limited 

 during the lifetime of the individual. 

 The restriction of cell division is a 

 necessary consequence of the regulation 

 of body form just as the restriction of 

 changes of chemical constitution is a 

 consequence of the regulation of physico- 

 chemical conditions within the organ- 

 ism. The restriction of cell growth 

 extends even to the germ cells, since un- 

 controlled development of such cells 

 within the body would lead to disaster 

 exactly as uncontrolled development of 

 epithelial or glandular or connective 

 tissue in malignant growths finally 

 leads to the death of the organism. 

 The germ cells of higher organisms have 

 lost the power of parthenogenetic divi- 

 sion, and develop only under such 

 conditions as will decrease, in large 

 measure, the danger to the parent 

 organism. The limitations to possible 

 change during the lifetime of any 

 individual preclude changes of suffi- 

 cient magnitude for purposes of evolu- 

 tion. The death of the unmodifiable 

 organism may be considered as an 

 adaptation^ from the point of view of 

 the species. 



The Evidence of Evolution 



THE THEORY OF EVOLUTION, with 

 special reference to the evidence upon which it 

 is founded. By William Berryman Scott, 

 Blair Professor of Geology and Paleontology 

 in Princeton University. Pp. 183, price $1.00. 

 New York: The Macmillan Co., 66 Fifth 

 Avenue, 1917, 



Dr. Scott thinks it is desirable for 

 students beginning work in science to 

 know on what evidence the theory of 

 evolution is based, instead of accepting 

 it meekly as an unquestionable dogma; 

 and in a simple manner he has considered 



the present status of the question; the 

 evidences from classification, domestica- 

 tion, comparative anatomy, embryo- 

 logy, blood tests, paleontology, geo- 

 graphical distribution, and experimental 

 breeding. The latter chapter is weaker 

 than the others. But as a whole the 

 book is commendable; it ought to be 

 very useful to beginners who want a 

 survey of the whole question, for most 

 of the accepted text-books that are 

 comprehensive are out of date. 



8 See Pike, F. H. Dr. Gaskell's Work on Organic Evolution. Science, December 4, 1914. 



5 The idea of death as an adaptation was put forth by Aug. Weismann, on somewhat different 

 grounds than those above outlined, in 1881. His lecture, Ueber die Dauer des Lebens, was printed 

 in 1892 in h.\?, Aufsalze tiber Vererhung. See also Gardiner, "Weismann and Maupas on the Origin 

 of Death," Marine Biological Lectures, 1890, Boston, 1891, p. 107. 



