17 



have produced splendid work on the receiib aad fossil 

 Brachiopoda. 



It is impossible, Miss Crane concluded, to go further 

 into details to night of the descent with modification among the 

 Brachiopoda. We have seen as we searched together the records 

 of the ancient fossiliferous rocks how the confines of the classes 

 merge into one another, — that orders converge and certain so- 

 called genera pass almost insensibly the one into the other. Our 

 knowledge has, indeed, advanced with giant strides of late, thanks 

 to the critical and searching investigations of the numerous able 

 scientists of diverse nationalities interested in this group of 

 organisms, and to those of France and America in particular. I 

 feel sure there is awaiting us in the not far distant future a com- 

 plete demonstration of the evolution of the Brachiopoda. 



WEDNESDAY, JANUARY 1 0th, 1894. 



NATURAL SELECTION AND EVOLUTION, 



BY 



MR. E. T. WYNNE, M.B. 



After briefly considering the various kinds of objections 

 urged against Darwinism, and instancing some of the commonest 

 misapprehensions of the theory, the writer proceeded to show by 

 quotations the significance of the expression natural selection aa 

 used by Darwin, and its limitations. The attempts to formulate a 

 theory of evolution up to the time of Darwin and Wallace were 

 indicated, especially the theory of Lamarck. Darwin and 

 Wallace showed that the origin of present species was earlier 

 species, and that their existence was due to the result of heredity, 

 variability, natural selection, and some other factors. Natural 

 Selection, which implied a struggle for existence, was the most 

 important factor in determining the direction of evolution. 



The evidence of a wide-spread struggle for existence was 

 examined, and examples of extreme variability in higher animals 

 were given. 



Variations may occur not only in the adult, but also in 

 utero, and probably in the ovum itself. 



The occurrence of transposition of the viscera was an instance 



