150 PROBLEMS OF EVOLUTION 



stages through which a human embryo passes, then it becomes 

 possible to believe in evolution. But difficult questions arise, 

 and perhaps the most difficult is this : when in the animal series 

 did consciousness first make its appearance ? We cannot tell 

 how far the lower animals are conscious, so that it cannot be 

 expected that any direct evidence should be obtained to enable 

 us to answer the question definitely. Yet an evolutionist must 

 not complain if an opponent argues thus : " Can you account for 

 consciousness on evolutionary principles ? If you have to assume 

 that at a certain stage consciousness was not evolved, but im- 

 planted, then your whole theory has received a fatal blow. A 

 law that has only a partial operation, dealing with only some of 

 the phenomena of animal life, is an absurdity." With this last 

 statement everyone must agree. As evolutionists, then, we are 

 bound to hold that consciousness in its highest form is the cul- 

 mination of a long series of stages of development beginning 

 Conscious- with something dim and rudimentary. We are bound to believe 



ness as- fa%t it is co-extensive with life, whether animal or vegetable. 



sumed in , . . r 



the lowest But low down in the scale it is, or course, so rudimentary that, 

 organisms tQ use p ro f essor Mark Baldwin's expression, " our terms become 

 eviscerated of their meaning." 1 As the criterion of mind we 

 may adopt selective reaction. Any organism, whether vegetable 

 or animal, selects what it requires as food and rejects what is 

 unsuitable. In the lowest stages of animal life, and in those 

 strange forms which hover between the animal and vegetable 

 kingdoms, it is wonderful what sensory and mental phenomena 

 big words, but justified by the facts present themselves for 

 our study. Has not M. Binet written a book on the Psychic Life 

 of the Micro-organisms ? 2 



Euglena and others have pigment spots which, probably, are 

 so far eyes that they enable them to move towards the light. 

 A volvox consists of a colony of organisms, each of which has 

 two flagella or threads of protoplasm. Since all these fiagella 

 swing in time together we must assume that there is the equiva- 

 lent of a nervous system to co-ordinate their movements. Yet 



1 See his Mental Development in the Child and in the Race, pp. 208-214. 



2 Published in the Religion of Science Library at Chicago. 



