Mr. Ch. C. Babington 07i some species o/Cuscuta. 249 



having been formerly part of tbem. We know also from the ob- 

 servations of Mr. Darwin, that many large tracts in the Southern 

 hemisphere are undergoing undulations of surface similar to those 

 required by my hypothesis, so that on the whole I think I have 

 left no point exposed, in which the assumption of a cause that is 

 insufficient or improbable under the circumstances will invalidate 

 my argument. After all it must be understood that I only offer 

 an hypothesis that appears to me probable to explain a phseno- 

 menon of great and acknowledged difficulty, and no one can be 

 more thoroughly aware than myself that there must always be a 

 wide and strongly marked distinction between such hypothetical 

 explanations and the numerous well-founded deductions with 

 which geology abounds, and which are unchangeable and un- 

 answerable, because founded solely on the consideration of un- 

 doubted facts. I need not however add any remarks to illustrate 

 the benefit resulting from the fair and unprejudiced discussion of 

 the class of explanations which I now offer. 

 Jesus College, Cambridge, March, 1844. 



XXXI. — On some species of Cuscuta. By Charles C. Babing- 

 ton, M.A., F.L.S., E.G.S. &c.* 



[With a Plate.] 



It is now some years since my attention was first di'awn to the 

 structure of the corona, the prominent parts of which form what 

 are usually denominated scales, in the interior of the tube of the 

 corolla of the genus Cuscuta ; but of which the existence in some 

 species, C. europcea for example, is denied by several eminent bo- 

 tanists ; and having soon become convinced of its presence in that 

 plant, and also that the general shape and direction of its pro- 

 cesses would furnish valuable characters for the discrimination of 

 species in this genus, in which so few tangible points are afforded 

 for that purpose, I presented to the Linnsean Society of London 

 the results of an examination of those species which were within 

 my reach in the form of two short papers which it did me the 

 honour to publish in its Transactions, vol. xviii. p. 213 and 563. 

 Having since that time become more practised in the exami- 

 nation of such mimite and inconspicuous objects, I have ascer- 

 tained that the figures then published do not represent the cha- 

 racters of those curious organs with sufficient accuracy, and have 

 therefore carefully prepared other drawings of the interior of the 

 flowers of the species gathered in Britain, with the exception of 

 C. Epilinum, which is well represented by Mr. Sowerby in the 

 ^^Suppl. to Eng. Bot.^ (vol. iii. tab. 2850), and in which the cha- 



* Read before the Botanical Society of Edinburgh, Feb. 8, 1844. 



