92 LECTURES 



and so, however intense the interest they may excite, they 

 can create no such thing as revolutionary surprises. They 

 will have, however, beyond all doubt, the effect of con- 

 stantly making clearer and clearer our conceptions of the 

 material scheme of the universe; the operations of natural 

 laws; and the interrelationship and interdependence of all 

 living things since life first appeared upon earth. It is 

 this kind of progress which is taking place at the present 

 hour, and will continue just so long as the mind of man 

 pleases to carry his inquiries and his researches into such 

 fields; and there appears to be no evidence at this time of 

 his relinquishing them. 



As has already been pointed out, the kno'vn phenomena 

 of biology comprised by the several sciences of mor- 

 phology, physiology and distribution are constantly lead- 

 ing us up, face to face, to that question of all questions, 

 the origination of living matter upon this planet, and the 

 causes which have led to it. Such knowledge as we 

 possess and in any way sheds any light upon this~subject, 

 is referred to as I have already said in that fourth 

 department of biology designated, as you know, as 

 aetiology; and it, in its present stage of development, 

 must be considered quite in its infancy. Especially must 

 this be regarded as the case, inasmuch as many of our 

 most competent living biologists are of the opinion, an 

 opinion shared by myself, that we are as yet in absolute 

 ignorance of the causes which have led to the origination 

 of living matter. From the very nature of the case 

 palaeontology will never be enabled to furnish us with 

 the direct evidence of the character of the primoidal 

 forms of living organisms, much less the proof as to how 

 those forms were first endowed with life. Still, evidence 

 of another kind, and most conclusive evidence, leaves no 

 doubt in our minds as to what the character of those 

 primoidal forms must have been, though that evidence 

 leaves us still utterly in the dark as to how life arose in 

 them. So far as our present-day knowledge carries us, 

 everything seems to point to the conclusion entertained 

 by most scientists that all planets and stars, alike, now 

 composing the universe, are either at present In a gaseous 

 state or have at some time or other passed through such 

 a stage. Further, we have every reason to believe that 

 this planet has likewise passed through a similar stage, 

 and that being the case its condition at that time must 

 have been Such that no living matter could have possibly 

 existed upon it. From this we are led to infer that liv- 

 ing matter must originally have arisen from non-living 



