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SCIENCE 



[N. S. Vol. XXXVI. No. 921 



form of life as we know it. All physiolo- 

 gists hold to the dictum: Omne vivum ex 

 vivo, and some say: Omne vivum ab eter- 

 nitate ex vivo. However this may be, the 

 primordial forms of life have developed into 

 the present forms. The simple in struc- 

 ture and function has become more com- 

 plex in both these directions. The unicel- 

 lular has evolved the multicellular. The 

 undifferentiated protoplasm, under the 

 stimulation and guidance of natural selec- 

 tion and environment, forces which we 

 with all our studies only vaguely compre- 

 hend, has been differentiated into the tis- 

 sues, systems and organs possessed by the 

 world of life as it exists to-day. Soft tis- 

 sues have protected themselves with carti- 

 laginous and bony structures. Prom the 

 invertebrate the vertebrate has developed. 

 Organs especially devoted to digestion and 

 assimilation have been evolved. Muscles 

 for locomotion have come into existence. 

 The vascular systems for the distribution 

 of blood and lymph have been slowly and 

 gradually elaborated, and every part of the 

 complex and highly developed animal has 

 been placed under the control and direction 

 of the nervous system. The highest prod- 

 uct of this wonderful and complicated de- 

 velopment is man. Science has not only 

 taught, but has demonstrated, all these 

 things. Man, though far still from perfec- 

 tion, has reached a stage when he has be- 

 come the most powerful and direct agent 

 in evolution. He takes the grasses of the 

 field, the flowers of the plains, the trees of 

 the forest, the lower animals in their native 

 states, and makes them almost anything he 

 wishes. By breeding and selection, by al- 

 tered and improved environment, and by 

 modification and control of the conditions 

 of life he is able to do these things. From 

 prehistoric times he has been cultivating, 

 developing and improving the grains which 

 serve him and his dependent animals as 



foods. With the dog, horse and cow he has 

 developed special breeds to suit not only 

 his needs, but even his whims. He has 

 filled his gardens with a profusion and 

 variety of flowers such as unaided nature 

 has never produced. His orchards furnish 

 his table with luscious fruits, so attractive 

 in appearance, so great in size and so deli- 

 cious in flavor that one can hardly realize 

 that they have come from the wild varieties. 

 Natural selection has been largely replaced 

 by human selection, and who shall say that 

 this is not natural ? But best of all is the 

 fact that man is himself an animal, yes, all 

 animal, and therefore capable of being im- 

 proved by breeding, selection and improved 

 environment. Were man, even in part, 

 other than animal or supernatural, and not 

 influenced by natural and controlable con- 

 ditions, the hope of his improvement would 

 not be so great. A supernatural force, if 

 there be such, is one which man can not 

 know, can not study, can not modify, and 

 if such a force controls the destiny of the 

 race, man's attempts to improve his kind 

 must be futile. A philosophy founded 

 upon such a belief leads nowhere, stimu- 

 lates to no good deed, and is barren and 

 dead from the start. On the other hand, 

 the belief that man himself is the most po- 

 tent factor in evolution should call out the 

 best effort in every one interested in the 

 welfare of his kind. If my work can make 

 two blades of grass where only one has 

 grown, can so improve the native grain, 

 which barely returns the seed sown, that it 

 will produce a hundredfold; can convert 

 the diminutive, sour, wild apple into the 

 large, mellow, delicious pippin; can con- 

 vert the native, scraggy pony, barely sub- 

 sisting on the sparse growth of his native 

 range, into the high-bred, well-developed, 

 spirited, intelligent horse; can change the 

 thieving, slinking wolf that once followed 

 the nomadic man in order to feed upon the 



