THE OTTAWA NATURALIST 



Vol. XXVI. MARCH, 1913 No. 12 



SOME CONDITIONS OF PROGRESS IN THE PLANT 



WORLD.* 



By W. T. MacClement, D.Sc, Professor of 

 Botany, Queen's University. 



There is no unanimity as to the meaning of the term 

 progress, but I shall use it in the ordinary sense of change, from 

 simplicity of structure to complexity, that is from uniformity of 

 parts to specialization of parts, from every part doing all kinds 

 of work to complete division of labor. 



I shall ask you to imagine first a lifeless world in which the 

 only changes were physical and chemical. Condensation, solu- 

 tion, diffusion, combinations, and decompositions all went on 

 vigorously in warm moist surroundings. This may have gone 

 on for ages, but finally, in all probability, as the climax of a long 

 series of combinations and rearrangements, some of these 

 chemical changes resulted in the formation of an unstable, 

 gelatinous substance which we call Protoplasm. In spite of much 

 serious study and long continued experimentation man has not 

 yet quite mastered the chemical processes involved in the build- 

 ing up of protoplasm. We know that it is made of carbon, 

 hydrogen, oxygen, nitrogen, phosphorus and sulphur "the dust 

 of the earth" and that it is probably a water solution of 

 proteids. Well, this translucent semifluid substance protoplasm 

 was siezed upon by a new force which gave the protoplasm 

 qualities in which it differed in a marked way from any other 

 chemical compound. One of these qualities is the ability of 

 protoplasm to change many other substances into its own sub- 

 stance, thus increasing the quantity of protoplasm. This ability 

 is not possessed by anv other kind of matter known to man. We 

 call this new force Life, and one of the notable powers of Life is 

 this, of giving to protoplasm the power to assimilate food, to 

 grow thereby and also to divide itself into two or even many 

 parts, each of which retains all the distinguishing qualities of the 

 parent mass. 



*Lecture given before the Ottawa Field-Naturalists' Club, Feb. 25th, 1913. 



