. 



GREAT STEPS IN EVOLUTION 95 



into intelligent expression where there is 

 perceptual inference. Finally, in man, with 

 his conceptual inferences, intelligent behaviour 

 becomes rational conduct. 



PKOGRESS ALONG MANY LINES. In his 

 interesting " Evolution of Plants," Dr. Scott 

 refers to the important fact that at a time so 

 remote as the Devonian period, when there 

 were no backboned animals higher than fishes, 

 a very high level of organization had been 

 reached by the plants. There were in those 

 days ferns and horsetails, club-mosses and 

 Pteridosperms, and many other plants of 

 high degree; what has happened since has 

 been specialization rather than great advance. 

 It is true that the fern-like Pteridosperms gave 

 rise to the world- wide Mesozoic Cycadophytes, 

 and, in still later times, to the true Flowering 

 Plants, but there was no great new organic 

 invention like that of the seed, for which the 

 flower is but the protean birth-robe. Since 

 that, progress has been in the intensive 

 colonization of the earth and in detailed 

 adaptations, vegetative and floral, manifold 

 and exquisite. 



In thinking of this, we must remember, in 

 the first place, that while the Devonian period 

 is inconceivably remote, there was an equally 

 inconceivable stretch of ages before it, during 



