94 SIR WILLIAM FLOWER CHAP. 



In his address he said : 



The doctrine of continuity, or of the direct relation of an 

 event to some preceding event, according to a natural and orderly 

 sequence, is now generally recognised in the organic world ; and 

 it is a curious circumstance that though the modern expansion of 

 this doctrine, as applied to the living inhabitants of the world, 

 appears to many so startling, and has met with so much opposi- 

 tion, it is in a more restricted application a very old and wide- 

 spread article of scientific as well as of popular faith. The 

 expansion of the special branches of knowledge affecting our 

 views upon this subject has taken place in many different direc- 

 tions, of which I can here only indicate the most striking. 



1. The discovery of enormous numbers of forms of life the 

 existence of which was entirely unknown a hundred years ago. 

 The increase of knowledge in this respect is something incon- 

 ceivable to those who have not followed its progress. Not only 

 has the number of well-defined known species multiplied pro- 

 digiously, but infinite series of gradations between what was 

 formerly supposed to be distinct species are being constantly 

 brought to light. 



2. Vast increase in the knowledge of the intimate structure 

 of organic bodies both as revealed by ordinary dissection and by 

 microscopic examination, a method of investigation only brought 

 to perfection in very recent years. 



3. The comparatively new study of the geographical dis- 

 tribution of living things, which has only become possible since 

 the prosecution of the systematic explorations of the earth's 

 surface which have distinguished the present century. The 

 results of this branch of inquiry alone have been sufficient to 

 convince many naturalists of the unsoundness of the old view of 

 the distinct origin of species, whether created each in the region 

 of the globe to which it is now confined, or, as many still imagine, 

 all in one spot, from which they have spread themselves, un- 

 changed in form, colour, or other essential attributes, to their 

 present abodes, however diverse in climate and other environ- 

 ments or conditions of existence. 



4. Lastly, though most important of all, must be mentioned 



