II THE PROGRESS OF SCIENCE 59 



there are numerous excellent summaries of the 

 progress of various branches of science, especially 

 up to 1881, which was the jubilee year of the 

 British Association. 1 And, with respect to the 

 biological sciences, with some parts of which my 

 studies have familiarised me, my personal experi- 

 ence nearly coincides with the preceding half- 

 century. I may hope, therefore, that my chance 

 of escaping serious errors is as good as that of 

 any one else, who might have been persuaded to 

 undertake the somewhat perilous enterprise in 

 which I find myself engaged. 



There is yet another prefatory remark which it 

 seems desirable I should make. It is that I think 

 it proper to confine myself to the work done, 

 without saying anything about the doers of it. 

 Meddling with questions of merit and priority is a 

 thorny business at the best of times, and, unless 

 in case of necessity, altogether undesirable when 

 one is dealing with contemporaries. No such 

 necessity lies upon me; and I shall, therefore, 

 mention no names of living men, lest, perchance, 

 I should incur the reproof which the Israelites, 

 who struggled with one another in the field, 

 addressed to Moses " Who made thee a prince 

 and a judge over us?" 



1 I am particularly indebted to my friend and colleague, 



or Riicker, F.R.S., for the many acute criticisms and 



ions on my remarks respecting the ultimate problems of 



. with which he has favoured me, and by which I have 



greatly profited. 



