YEAR by year the word 'Evolution' becomes diffused more widely through our literature, and the central idea which it implies grows familiar to an ever-increasing multitude of readers. We have witnessed within the last few years a marvellous awakening of interest in the minds of the public generally to questions of science, and it so happens that a discussion of the Doctrine of Evolution has been more or less directly involved in those departments of Science and Philosophy which have during this period received the largest share of popular attention.

Perhaps the greatest impetus was given to the spread of the doctrine about fourteen years ago, by the publication of Mr. Darwin's now celebrated "Origin of Species." This volume has been followed by quite a library of works and memoirs on the same subject-partly scientific and partly popular. From about the same date also, Mr. Herbert Spencer has been engaged in systematically elaborating the

principles of an all-comprehensive Evolution Philosophy, and the results of his genius and labour are now undoubtedly influencing the thoughts of a rapidly widening circle of readers. Both in this country and abroad the doctrine of Evolution is gradually but surely gaining ground amongst the most reflective, and although many other writers have been more or less influential in determining this result, it has been in the main brought about by the two above mentioned.

It

Evolution implies continuity and uniformity. teaches us to look upon events of all kinds as the products of continuously operating causes-it recognises no sudden breaks or causeless stoppages in the sequence of natural phenomena. It equally implies that natural events do not vary spontaneously. It is a philosophy which deals with natural phenomena in their widest sense: it embraces both the present and the far-distant past. It seeks to assure us that the properties and tendencies now manifest in our surrounding world of things, are in all respects similar to those which have existed in the past. Without a basis of this kind, the Evolution Hypothesis would be a mere idle dream. Uniformity is for it an all-pervading necessity. Starting from facts of daily observation and from scientific experiments, the properties and