424 TRANSACTIONS OF THE CANADIAN INSTITUTE. [Vou, VIII. 
of the problem arose from the fact that little was known about the chem- 
istry of the vital processes and even of the physical basis of life itself, 
that is, what has been commonly called protoplasm. Indeed the imag- 
ination was tasked to explain how a mixture called living matter could 
manifest the changes and transformations which are characteristic of 
life, the phenomena of assimilation, growth, reproduction and the trans- 
mission to the off-spring cells of the properties of the parent cells, the 
capacity to go on endlessly, if favorable environing conditions are main- 
tained. These features of living matter have no counterpart in what is 
called dead or inorganic matter, and the gulf between the living and the 
non-living was not supposed to be bridged over by any means at the 
command of the thinker or the man of science. Is it any wonder that 
half a century ago when Darwin was writing his “ Origin of Species” he 
should have used in the closing chapter of that work language which 
implied that he believed the one primordial form, from which all living 
things on this earth have had their origin, was called into existence by 
the direct act of a Creator? He laboured to show that all living forms 
arose from simpler forms in the past and that this evolutionary process is 
still going on and thus he accounted for the richly varied fauna-and flora 
of the globe, but his mind evidently shrank from offering a solution of 
the question how the one parent form of all arose in the far distant past. 
This was not, however, in every case the attitude of those who gave 
thought to the question. Twelve years after the publication of the 
“Origin of Species,” that is in 1871, Lord Kelvin,* then Sir William 
Thomson, advanced the view that the impossibility of bringing about 
the conversion of lifeless into living matter without the aid of already 
living forms was as definitely established as is the law of gravitation 
and that consequently the only way to account for life on this planet 
was to suppose that it was originally borne by meteorites from outside 
the solar system. To this latter hypothesis he gave his full adhesion. 
This theory did not receive general assent. It was recognized that 
even if living organisms could be so borne to our planet they would be 
destroyed by the intense heat generated when the meteorites began to 
penetrate the earth’s atmosphere. Further the minimum amount of 
time required to transport such organisms on meteorites from the stellar 
system nearest to our own, namely that of ¢ Centauri, would be about 
62,000,000 years, and this at a speed of about 40 miles an hour and it 
would take nearly 140 years in going from Mars to the earth, at the 
same rate of speed. This length of time put the theory out of court, 
*Presidential Address, British Association Meeting for 1871. 
