44-2 



Progress of Geology. 



Some of these germs were so far advanced as to have put forth 

 the rudiments of two or three leaves {cd)^ others less so\ef), 



197 



V ^ e d 



These plants often occur in little clusters of half a dozen or 

 more close together, which may be accounted for by several 

 of the germs arriving at perfection, whilst the rest perish. 

 Otherwise, so far as I have observed, the plant is generally 

 continued by a single offset, and three or four of the old de- 

 cayed bulbs may be found, one below the other, among the 

 peat, and still attached to the living stem. 



This and Malaxis LoesebV are probably truly parasitic. 

 I remain, Sir, &c. 

 Cambridge^ Aug, 14. 1828. J. S. Henslow. 



Art. X. Progress of Geology. By R. C. T. 



In a former article (p. 249.), devoted to the consideration 

 of two interesting geological memoirs, it was judged a fitting 

 opportunity to contribute a series of preparatory illustrations 

 of stratification, partly original, and the remainder selected 

 from authentic data.* If we deviated somewhat from the 

 strict course of an elementary treatise, and brought forward 

 matter which should have formed a section at a more advanced 

 stage, it will, perhaps, be conceded that those details were not 

 unseasonably introduced. Our progress will henceforth be 

 more regular. In the limited space which can here be appro- 



* During the progress of this article, all the illustrations which are not 

 expressly accounted for, may be considered as original. 



To those who are familiar with the gigantic scale on which the geology 

 of some other countries is exhibited, the examples we have selected may 

 appear trivial ; but it must be remembered that our main design is the 

 illustration of English geology. 



