BY THE PRESIDENT. 89 



extinction of species, and of wliole groups of species, which has 

 played so conspicuous a part in the liistory of the organic worhl, 

 ahuost inevitably follows from the principle of natural selection ; 

 for old forms are supplanted by new and improved forms. Neither 

 single species nor groups of species reappear when the chain of 

 ordinary generation is once broken." The remainder of this para- 

 graph is considerably qiudified by the use of such words as "in 

 some degree," and "generally"; and it is therefore not open to 

 any critical comment. 



Page 424. — " 1 believe that animals are descended from at most 

 only four or five progenitors, and plants from an equal or lesser 

 number. Analogy would lead me one step further, namely, to the 

 belief that all animals and plants are descended from some one 

 prototype." 



' The Origin of Species ' is couched in a most attractive style of 

 scientific and philosophical candour ; but I venture to think that 

 the hypothesis advanced or advocated by the author is inconclusive 

 and unsatisfactory. 



I may here parenthetically observe that both the Darwins had 

 been to a certain extent anticipated in some of their conclusions. 

 In 1733 Sellius (' Historia naturalis Teredinis seu Xylophagi 

 marini'), a learned lawyer and philosopher of Utrecht, and a 

 Fellow of our R )yal Society, disputed the common opinion which 

 was entertained in his time by some neoteric writers that all living 

 beings had descended from original forms or types. 



That part of Charles Darwin's work which proposes a vera causa 

 for the origin of species by means of what he calls "natural 

 selection " does not seem to have met with general acceptance, 

 even fi'om Professor Huxley, who otherwise approves the doctrine 

 of evolution. It is a very convenient Deus ex macJiina for solving 

 all difiiculties. Nor, when he added a subsidiary cause in " sexual 

 selection," is that opinion shared by Mr. Wallace, who was the 

 co-originator of the first-named and principal theory. 



What are the facts, so far as geology can teach us, with regard 

 to the origin of species ? 



Our knowledge of the earliest life-history of the world is entirely 

 derived from the study of the fossilized remains of marine animals. 

 It is unquestionable that the geological, or rather the pala^onto- 

 logical, record is imperfect, especially when we consider that more 

 than three-fourths of the earth's surface is covered by the sea, and 

 is therefore inaccessible to us, and also that what we now call 

 the primeval formations, such as the "fundamental gneiss" of 

 Murchison and of the Laurentian rocks, have been subjected, perhaps 



