of those who are in the habit of speaking of simple and complex forms can 

 give a rational explanation of what he means by the phrases he employs. 

 What is generally meant by the simplest form of living matter is that when 

 it attains its highest form of development it is still a simple thing, and what 

 seems to be understood by that of the greatest complexity is, that when 

 it attains its highest degree of development certain marvellous structures 

 are produced ; but when we come to look at the living matter itself there is 

 no difference to be discerned by any means of examination yet adopted 

 between the two forms. The living matter, which, at the very earliest 

 period of his development, represents man, is, as far as I know, not dis- 

 tinguishable from the forms of living matter of which the simple bodies 

 Dr. Wallich has so lucidly described to us are made up. And therefore 

 the difference cannot be chemical. Neither can it be called physical, nor 

 mechanical, nor can it be due to difference in machinery or mechanism, for 

 none is to be discovered. The difference is enormous, and it is of a most 

 remarkable kind, but it is not to be explained by any facts in physical science 

 with which we are acquainted. All we know is, that under certain conditions 

 one form of living matter grows and produces a certain kind of structure, 

 and that under different conditions certain other forms of living matter grow 

 and produce a structure that is totally different. The difference between the 

 two is not in molecular or chemical constitution. They do not remarkably 

 differ in chemical composition, and we may safely say it is impossible thus 

 to explain the difference. That is the whole of the matter ; the difference in 

 the results cannot be explained by physics or chemistry, and I do not think 

 it ever will be so explained. The difference is one which can only be spoken 

 of under another term altogether, and this is a word to which many object 

 very strongly. I allude to the word " vital." The difference in question is a 

 vital difference, dependent not on a property which belongs to matter itself 

 as matter, or derived from any properties in connexion with the elements 

 which enter into the composition of the living matter. Whether the genera- 

 tion of living matter was spontaneous or not cannot be proved, but much 

 scientific speculation is built upon the theory of spontaneous generation. 

 However necessary such a theory may be to the doctrine of evolution, there 

 are no scientific facts which can at all warrant the conclusion that non-living 

 matter only, under any conceivable circumstances, can be converted into 

 living matter, or at any previous time has, by any combination, or under any 

 conditions that may have existed, given rise to the formation of anything 

 which possesses, or has possessed, life. (Applause.) 



