280 



contrary to all our experience of rate of change at present : 

 two assumptions have to be made to get rid of this diflSculty ; 

 first, the usual one of inconceivably long periods of time; 

 and, secondly, the supposition that the changes took place 

 with far greater rapidity then than now, of which, however, there 

 is no proof whatever. On the contrary, the force of heredity is 

 said to be always greatest nearest to the origin of the form. 

 It is a somewhat singular circumstance, and not without a 

 bearing on our question, that in the case of the ammonites we 

 find the first forms closely coiled, but one of the principal last 

 forms — the baculites — is absolutely as straight as the ortho- 

 ceratite. If the process from the straight form to the curved 

 is to be called evolution, by what name shall the reverse be 

 distinguished ? I show you a baculites, that you may see that 

 it is not merely an uncoiled ammonite, any more than an 

 orthoceratite is not merely an uncoiled nautilus, — but both are 

 distinct forms, not degenerate but independent creatures. 



The importance of the subject, as now elevated into a test 

 case, must be my apology for adducing some authorities on 

 both sides, in addition to those previously mentioned. 



We may quote on the one side the utterances of Professor 

 Flower at the recent Church Congress at Reading, who boldly 

 says : — 



" The opinion now almost, if not quite, universal among 

 skilled and thoughtful naturalists of all countries, and what- 

 ever their beliefs on other subjects, is that the various forms 

 of life which we see around us, and the existence of which 

 we know from their fossil remains, are the product, not of 

 independent creations, but of descent, with gradual modifica- 

 tion from pre-existing forms.^^* He afterwards, however, 

 states that direct proof of the theory is wanting. 



On the other hand. Dr. Duncan, in his presidential address 

 to the Geological Society in 1878, comments on the difficulties 

 of evolution in reference to the nautiloids as follows : — '^ Every 

 student of palgeontology must be impressed at the commence- 

 ment of his studies with the excessive variety of form dis- 

 played by the tetrabranchiate cephalopoda, and when informed 

 that it is produced by natural selection wonder is felt that 

 the shapes assumed had a curious resemblance during the same 

 geological age over the whole world, and that the genus 

 Nautilus should have remained so little altered in spite of 

 the struggle for existence, the survival of the fittest, sexual 

 selection, and adaptive modification.''^ t 



* Nature, October 11, 1883. + Quarterly Journal, G. S., vol. xxxiv., p. 68. 



