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PRESIDENT S ADDRESS SECTION D. 



solving the great problem of all Science — find the prime motor of 

 secondary causes. Meanwhile it is a fact fraught with significance 

 to a thoughtful man that all living things are of the same vital 

 substance with himself. 



Reflection on the oneness of life, fruitful of good to the moraliser 

 as to the knowledge-seeker, becomes far more edifying to both 

 when life appears to the mind steadfast in continuity. 



In the early days of biology its ablest expounders rarely or never 

 doubted that, under favorable circumstances, life could spring up 

 where no life was before. The fact that it commonly entered its arena 

 by process of descent did not compel them to question the truth of 

 the general opinion of the age that lix-ing things frequently issued 

 fatherless from the womb of unknown conditions. They had not, 

 indeed, a broad unswerving base of experience on which to found 

 a generalisation which should exclude that assumption; nor was 

 the tenet held fast by all around them that life, as ordinarily 

 acquired, is a special gift to the unborn, a guide to the path of 

 heterodoxy. It was by slow degrees that observation gave form to 

 suspicion, and, pouring down a fuller volume of rays, ripened it 

 into certainty that in the ordinary course of nature abnormal 

 generation was not in the least likely to occur under any con- 

 tingency. In our own day attempts to prove by exact experiment 

 that the well-tried maxim of biology, " Life from the living only," 

 may not be unexceptionallj^ true, shows that the inheritors of the 

 discredited hypothesis still number among them men of scientific 

 training ; but these are certainly not the revivex's of an obsolete 

 doctrine That absence of biological knowledge which permitted 

 a past generation to believe that geese of certain kind were the 

 fruit of a tree, and which among our Australian selves — even 

 amongst our educated selves — sees no difficulty in maintaining that 

 the young kangaroo is born on the nipple of its mother, will long 

 bar the mind against the conviction that external circumstances 

 alone are powerless to produce life, will long throw the imagination 

 open to entertain a fallacy which may indeed be less grotesque but 

 is not less inconsequent than these. Biology does not, of course, 

 assert dogmatically that the reintegration of life, which is really 

 meant by the term " spontaneous generation," is theoretically im- 

 possible ; it seems to her only less conceivable than that primaeval 

 integration of life, which, if terrestrial, was in a sense spontaneous 

 generation, but she does say that, after decades of toilsome research 

 into the obscurest recesses of nature by her acutest experts, she 

 has never met with an instance in which life came into existence 

 by its own will — an obvious absurdity — or by abnormal means. In 

 defiance of the advocates of spontaneous generation she declares 

 that every plant or animal is, in its inception, necessarily a part of 

 a similar body pre-existing. In opposition to mistaken conceptions 

 of generative methods founded on inconclusive observation she 

 teaches that these are not subject to violent revolutionary changes 



