200 ROYAL SOCIETY OF CANADA 



of time. In animals which have acquired a liigher organism tlie adjust- 

 ments are more complex, both because the reactions are more varied and 

 because they cover a longer period of time. Thus the jelly fish depends 

 upon such food as happens to come within its reach, seizing from 

 moment to moment that which it encounters; but the lobster pursues 

 its food, making complicated movements in order to reach and seize it. 

 One can trap a lobster easily; I doubt if one can tra,p a jelly fish at all. 

 The next great advance is marked by the establishment of communi- 

 cation between individuals of the same species. About this phenomena 

 we know exceedingly little; the investigation of it is one of the most 

 important duties' of the comparative physiologist. Its bionomic value is 

 obviously great for it allows an individual to utilise the experience of 

 another as well as its own. AYe might indeed compare it with the addi- 

 tion of a new sense, so greatly does it extend the sources of information. 

 The communication between individuals is especially characteristic of 

 vertebrates, and in the higher members of the snb-kingdom it plays a 

 great role in aiding the work of consciousness. In man, owing to arti- 

 culate speech, the factor of communication has acquired a maximum 

 importance. TJie value of language, our principal medium of commu- 

 nication, lies in its aiding the adjustment of the individual and the race 

 to external reality. Human evolution is the continuance of animal 

 evolution, and in both the dominant factor has been the increase of the 

 resources available for consciousness," 



Professor Minot believes that consciousness is a real and dominant 

 factor in the evolution of animals, that it affects the vital processes : 

 '•' There is in my opinion no possibility of avoiding the conclusion that 

 consciousness stands in immediate causal relation with physiological 

 processes." 



While I may not be ready forthwith to admit that Minot's dictum 

 in regard to consciousness is perfectly satisfactory, it has been gratifying 

 to me to find so many views similar to those which I have been myself 

 accustomed for the past few years to elaborate in my lectures to 

 students, expressed, so clearly and vigorously in this address. 



H. S. Jennings, who has worked much on the reactions of infu- 

 soria, after criticising the conclusions of Hodge and Aikins, which he 

 concludes go too far, refers to Minot's views. He thinks that by this 

 writer's criterion we should clearly have to attribute consciousness to 

 Stentor, for at times this creature inhibits reactions to stimuli, while 

 again it reacts strongly. Jennings is not, however, satisfied with 

 Minot's criterion for he believes that, '" Unconscious mechanisms can be 

 constructed and indeed do exist, in which there is' a dislocation in time 



