1904-1905.] 323 



Mr. R. S. Tliomi^son having been elected a member, the 

 proceedings terminated. 



EVOLUTION OF PLANT AS COMPARED WITH ANIMAL LIFE. 



The weekly meeting of the Club was held on the 25th 

 January. Mr. W. J. Fennell, M.R.I.A.I., presided, and Mr. 

 Alex. Milligan delivered a short address on " The Evolution 

 of Plant as compared with Animal Life." The speaker, after 

 dealing with various definitions, proceeded to trace briefly 

 the pedigree of some existing forms of plants and animals. 

 In the protozoa, he believed, were to be found the common 

 ancestors of both. After dealing with the unique power of 

 chlorophyll — itself a form of protoplasm — to build up organic 

 substance from inorganic matter, he pointed out that protozoa 

 afforded several examples of organisms furnished with this 

 chlorophyll, but which were considered too independent in 

 structure to be classed as either animals or plants according 

 to the ordinary conception of these terms. Nevertheless, he 

 believed that certain environments which necessitated the 

 continued functions of the chlorophyll in such organisms had 

 led to its sole use in their nutrition. This, with the concomi- 

 tant modification of structure which it involved, had led to 

 the gradual development of true plant forms. Animal forms, 

 he pointed out, must have been derived from forms of life not 

 furnished with chlorophyll, and which were, therefore, de- 

 pendent for sustenance on already existing organic matter — 

 always the main characteristic of the animal kingdom. After 

 touching upon the amazing faculty of selection and adapta- 

 tion manifested by protoplasm, even in the simplest forms of 

 life, the speaker concluded by alluding to the different charac- 

 ter of the modifications of form and structure resulting from 

 the fixed situation of the higher plants and their inorganic 

 environment as compared with those resulting from the 

 highly complex life and environment of animals; roughly in- 

 dicating the lines on which plant and animal anatomy had 

 developed. 



