THE 



GEOLOGICAL MAGAZINE. 



NEW SERIES. DECADE V. VOL. III. 



No. v. — MAY, 1906. 



OK.I<3-I3^-A.Xj Jk.I^TIGX.E!S. 



I. — Lamarck and Playfaik : A Geological Eetrospeot ov the 



Year 1802.i 



By Sir Archibald Geikie, Sc.D., D.C.L., LL.D., Sec. E.S., 

 President of the Geological Society. 



{Concluded from the April Number, p. 153.) 



IF Lamarck allowed his brilliant faculty of generalisation to lead 

 him far astray in his opinions regarding the origin of rocks, he 

 had formed a saner judgment on the causes that have developed the 

 present terrestrial topography. The first chapter of the " Hydro- 

 geologie " is devoted to a consideration of the natural results that 

 arise from the circulation of water over the surface of the land. 

 This subject, he remarks, affords less scope than any other for the 

 exercise of the imagination in framing hypotheses, for it can be 

 studied on a basis of facts which are generally familiar. Though 

 the question required to be considered in his treatise and was capable 

 of easy solution, yet it seemed to him to be novel, at least from 

 a general point of view, and to have been previously neglected by 

 physicists and naturalists. He appears to have formed his con- 

 clusions regarding it independently, and to have been unaware how 

 far he had been anticipated by previous observers. It is singular 

 that he makes no allusion to tlie work of his distinguished fellow- 

 countryman Desmarest, who some thirty years previously had 

 demonstrated, from a prolonged and minute investigation of the 

 volcanic history of Auvergne, that the valleys of that region have 

 been excavated by the streams which flow in them. He does not 

 refer to the enunciation of the same doctrine by De Saussure a few 

 years later in regard to the valleys of the Alps, nor to the clear 

 presentation of similar views by Hutton, whose system had been 

 expounded to French readers by Desmarest. But though he was 

 mistaken in supposing that the doctrine was novel, Lamarck was 

 not surpassed by any of his predecessors in the firmness with which 

 he espoused it, and in the clearness with which he presented it to 

 the world. Kealising so fully as he did the magnitude of the scale 



* Aa address delivered before the "Alliance Fraii9aise " in the Sorbonne, Paris, 

 on 26th February, 1906. 



DECADE V. — VOL. III. — NO. V. 13 



