on (he Erratic Fhenomena of Scandinavia. 116 



ciers, or to that of currents ; for, in either case, we could not 

 take the direction of the striae as the only indication of the 

 route taken by the agent which traced them, without taking 

 into account all the other marks which might serve to make 

 us acquainted with this direction. The problem is not be- 

 yond the means of solution, for M. A. Guyot has figured upon 

 the map the space occupied by the different glaciers which 

 formerly covered the plain lying between the Alps and the 

 Jura. But, besides the direction of the striae, he has taken 

 into account the mineralogical nature of the transported rocks, 

 their mode of dispersion, whether in a sporadical state, or in 

 the form of lateral, median, or terminal moraines. He has 

 followed these materials from the point of their departure in 

 the Alps to their point of arrival in the Jura, and he has 

 thus been enabled to circumscribe the domain of each glacier 

 with as much accuracy as we can trace the limits of a super- 

 ficial formation** 



Characters of the Transported Deposits m the north of Europe. 

 In the flat country, this formation presents itself sometimes 



* In his first toemoii*, M. Durocher had ascribed th6 sinuous canals, ramified 

 and anastomosing with each other, which he had seen on the shores of the sea, 

 to diluvian currents.* In the present, he remarks on the contradictions in the 

 explanations which have been given of them by MM. Agassiz,t Escher de la 

 Linth,J P. Schimper,§ and myself, j] Now, all the four of us have ascribed 

 the sinuous and anastomosing canals observed by M. Durocher to the action of 

 water ; only MM. Agassi z and Escher have considered the striae engraved in the 

 interior of these canals as the striae of glaciers. M. Schimper ascribes them to 

 the action of waves. For myself, I have not pronounced an opinion on the 

 origin of these striae, which were known to me, neither by specimens, nor de- 

 tailed description, nor by accurate drawings. Accordingly, in my first reply, 

 I have not spoken of these stria;, and, in my second, I have expressed myself 

 thus I " With th6 rest of M. Durocher's argument, supposing what I have not 

 said, namely, that the striae engraved in the interior of sinuous canals have been 

 produced by glaciers, I shall not occupy myself." It will thus be seen that we 

 agree as to tlie origin of these canals, only M. Schimper differs from MM. 

 Agassiz and Escher in the explanation of one of the details, the striae in their 

 interior. 



* See the form of those sinuous canals, Bulletin de la Boeiete Qeologique, 2d series, t. iii. 

 n. I., figs. 1, 5, and 8 ; that of the strice of glaciers, PI. II., figs. 3, 4, 5, and 6. 



t Comptes Rendiu de VAcademie des Sciences, t. xxi., p. 133. 15th Doc. 1845. 



I Bulletin de la Soci'ete Geologique, 2d series, t. iii., p. 230. 19th Jan. I&IO. 



§ Comptes Rendxtt de VAcademie des Sciences, t. xxii., p. 4^-5. 6th Jan. 1846. 



II linlletin de la Societe Oeologique, 2d series, t. iii^ p. HI. 15th Dec. 1840. 



