194 Dr Buckland on (he former Existence of 



connected with development. Whatever it may be, it must 

 be considered as the means of adapting the structure of the 

 animal to some peculiarity in its habits or economy. 



Explanation of Plate IP'. 



Fig. 1. The cells of the peculiar tissue : a, cell ; b, nucleus ; c, nucleoli. 



Fig. 2. Skeleton of the tail of orthagoriscus niola : a, fourteenth vertebra ; 

 b, fifteenth ; c, sixteenth ; d, seventeenth ; e, eighteenth ; /, interspi- 

 nous bones abutting against spinous processes of vertebra? ; g, rays of 

 caudal-fin. N 



On the former Existence of Glaciers in Britain. 



I. On the former Existence of Glaciers in Scotland. By 

 Dr Buckland.* 



Dr Buckland, in a Memoir on this subject read before the Geological 

 Society of London on the evenings of the 4th and 18th of November last, 

 commenced by observing, that, when his attention was first directed by 

 Professor Agassiz, in October 1838, to the polished, striated, and furrowed 

 surfaces of the rocks on the slopes of the Jura, near Neuchatel, as the ef- 

 fects of glaciers, he doubted the correctness of the inference ; but after 

 devoting some days to the examination of actual glaciers, and the effects 

 produced by them, he became a complete convert to the glacier theory, 

 as far as relates to Switzerland. On his return to Neuchatel, in the same 

 year, he informed M. Agassiz that he had noticed similarly polished and 

 striated rocks, in 1811, on the left side of the gorge of the Tay, near 

 Dunkeld, though he then attributed the appearance to diluvial action ; 

 that, in 1824, he had noticed, when in company with Mr Lyell, grooves 

 and striae on the surface of granite rocks, near the east base of Ben Ne- 

 vis ; and that near the base of Ben Wyvis, Sir G. Mackenzie pointed out 

 to him a high ridge of gravel, arranged obliquely across a valley, and not 

 explicable by any action of water. Those phenomena, however, since his 

 examination of the Swiss glaciers, he has been convinced, may be ex- 

 plained by the friction of ice upon rocks, and the production of transverse 



facts which must be explained before we can connect the length of the 

 latter in the embryonic and adult series with the length of the former. 



* We recommend to those interested in the system of glaciers, as taught 

 by Professor Agassiz, which is nearly that adopted by Dr Buckland and 

 others, to read previously Professor Agassiz's system, as explained by him- 

 self in a M ernoir entitled " Upon Glaciers, Moraines, and Erratic Blocks," 

 in vol. xxiv. of this Journal, extending from page 364 to page 383 ; or the 

 classical work, just published, entitled " Etudes sur les Glaciers. Par L. 

 Agassiz:." 



