18 PRESIDENT’S ADDRESS. 
means minimise the difficulties which attend the suggestion that the 
evolution of life may have occurred more than once or may still be 
happening, but on the other hand, it must not be ignored that those 
which attend the assumption that the production of life has occurred 
once only are equally serious. Indeed, had the idea of the possibility 
of a multiple evolution of living substance been first in the field, I 
doubt if the prevalent belief regarding a single fortuitous production of 
life upon the globe would have become established among biologists—so 
much are we liable to be influenced by the impressions we receive in 
scientific childhood ! ; 
Assuming the evolution of living matter to have occurred—whether 
once only or more frequently matters not for the moment—and 
in the form suggested, viz., as a mass of colloidal slime 
Further possessing the property of assimilation and therefore of 
pica th of growth, reproduction would follow as a matter of course. 
life. For all material of this physical nature—fluid or semi- 
fluid in character—has a tendency to undergo subdivision 
when its bulk exceeds a certain size. The subdivision may be into 
equal or nearly equal parts, or it may take the form of buds. In either 
case every separated part would resemble the parent in chemical and 
physical properties, and would equally possess the property of taking 
in and assimilating suitable material from its liquid environment, grow- 
ing in bulk and reproducing its like by subdivision. Omne vivum e 
vivo. In this way from any beginning of living material a primitive 
form of life would spread, and would gradually people the globe. The 
establishment of life being once effected, all forms of organisation follow 
under the inevitable laws of evolution. Ce n’est que le premier pas qui 
cotite. 
We can trace in imagination the segregation of a more highly 
phosphorised portion of the primitive living matter, which we may now 
consider to have become more akin to the protoplasm of organisms 
with which we are familiar. This more phosphorised portion might 
not for myriads of generations take the form of a definite nucleus, but 
is would be composed of material having a composition and qualities 
similar to those of the nucleus of a cell. Prominent among these 
qualities is that of catalysis—the function of effecting profound 
chemical changes in other material in contact with it without itself 
undergoing permanent change., This catalytic function may have been 
exercised directly by the living substance or may have been carried 
necessary that, as Pfliger assumed, the planet should have been at a former 
period a glowing fire-ball.’ He ‘prefers to believe that the circumstances 
which support life would also favour its origin.’ And elsewhere : ‘ Life is not 
an extraordinary phenomenon, not even an importation from some other sphere, 
but rather the actual outcome of circumstances on this earth.’ 
