great man, will have been made sufficiently plain, but I cannot flatter 

 myself that I have conveyed any adequate conception of him. 



In the summer of 1895, I went abroad, for the first time in seven 

 years, to attend the meetings of the British Association at Ipswich and 

 the International Zoological Congress at Leyden. There was time for a 

 hurried visit to Heidelberg, where my friends gave me a welcome of 

 delightful cordiality. My family spent the summer with my oldest 

 brother on Lake Muskoka. 



The Ipswich meeting, to the best of my recollection, was memorable 

 only for the announcement by Dr. Ross, of the British Army Medical 

 Service, of his demonstration that malaria was transmitted by the bite 

 of certain species of mosquito. This confirmed Koch's suggestion, 

 which, though a stroke of genius, was yet an unproved hypothesis. In 

 other respects, the meeting was very much of the usual sort, though I 

 enjoyed it greatly, as the opportunity of meeting many old friends. 



The Congress at Leyden was a much more brilliant affair, as it was 

 attended by the most eminent Zoologists of all countries. The outstand- 

 ing figure there was that of Professor August Weissmann, of Freiburg 

 in Baden, who had become the Pope of the Neo-Darwinists. He was 

 the first to give authoritative denial of the transmissibility of acquired 

 characters, which Darwin himself had accepted, and to set up Natural 

 Selection as the sole factor of organic evolution; he published a paper 

 entitled "The Omnipotence of Natural Selection." So widely did Weiss- 

 mann's views prevail in England and Germany that it was almost im- 

 possible, for a time, to secure publication for any paper that was in oppo- 

 sition to those views. Violent and angry partisanship characterised the 

 discussions and an intolerant fanaticism took the place of scientific 

 calm. The creed of the Neo-Darwinists was: "There is no god but 

 natural selection and Darwin is its prophet." The Leyden Congress was 

 the battleground, where some of these controversies were fought out 

 and where the interest was sustained to the end. 



The Congress was to open formally on a Monday morning, but most 

 of the visitors had arrived by Sunday evening, when they were assem- 

 bled in the suburban beer-garden belonging to one of the clubs. My 

 friend Hubrecht, of Utrecht, jumped up on one of the iron tables and 

 made an address of welcome, equally divided into German, French 

 and English. Not only were the three languages, all foreign to him, 

 correctly spoken, they were elegantly and beautifully spoken. When I 

 congratulated him on this remarkable tour de force, he laughed and 

 said: "Oh! well, we Dutchmen are compelled to learn foreign lan- 



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