TRANSACTIONS OF THE SECTIONS. 61 



thyolites so abundantly on the north side) he observed a coarse red conglomerate 

 about twelve feet thick, which, with the thin one containing the fish, and the inter- 

 mediate grits, he considered as the true representatives of the conglomerate de- 

 scribed by Mr. Murchison as extending from Monmouthshire into Pembrokeshire 

 along the base line of the carboniferous limestone, and sometimes attaining a thick- 

 ness of two hundred feet. On the evidence of this Bristol conglomerate and the 

 fish remains, Mr. Williams referred all above it to the early period of the mountain 

 limestone, and thus placed it in strict parallel with the alternations of limestone and 

 red sandstone delineated by Professor Phillips in four sectional columns in his work 

 on Yorkshire, as resting on the great conglomerate, in as many widely-remote locali- 

 ties. His views necessarily required or implied an original elevation above the sea 

 level, and a subsequent submergence of the old red sandstone to a great depth below 

 it; and this admitted, the red sandstone alternations of Mr. Phillips and the case of 

 the St. Vincent's Rocks are referable to detrital matter abraded from the slowly and 

 unequally submerging old red sandstone at the first formation of the mountain lime- 

 stone. From the constancy of this conglomerate so interposed between the old red 

 sandstone and carboniferous limestone, Mr. W. inferred that it chronicled an inter- 

 val in time sufficiently capacious for the reception of the so-called Devonian system, 

 (for that vast succession of mineral masses incompletely developed in the West of 

 England, by terminating upwards with the killas group,) whose true place in the geo- 

 logical scale was intermediate between the old red sandstone and mountain lime- 

 stone, and (except on their respective confines) perfectly independent of either. 



ZOOLOGY AND BOTANY. 



On the different Species of Cotton Plants, and of the Culture of Cotton in 

 India. By Professor Royle, M.D. F.R.S., of the East India House, 

 and of King's College, London. 



The author observed, first, that plants yielding true cotton were natives both of the 

 Old and of the New World, that the species (all referred to the genus Gossypium by 

 botanists) were distinct. India, for instance, produced two species, — 1, G. arboreum, 

 or tree cotton, nurma of the natives, with red flowers, little cultivated, though yielding 

 a fine silky cotton ; 2, G. herbaceum, the herbaceous or common Indian cotton, of 

 which there were several varieties, including the Dacca cotton. This species has been 

 spread from India to the south of Europe. Both these species have small seeds with 

 short adhering hairs under the cotton. There are also two distinct American spe- 

 cies : — 3, G. Peruvianum, or acuminatum, distinguished by its large black seeds, which 

 adhere to each other, and by its pointed fruit and leaves : this species yields the 

 Brazil, Pernambuco, Bahia, &c. cottons. 4, G. Barbadense, is so called from having 

 been early cultivated in Barbadoes. It has black Seeds, free of short hairs, and is the 

 same as the Sea Island cotton, and was long since introduced into the Islands of 

 Mauritius and Bourbon. From an examination of specimens and coloured drawings 

 this species appeared to be identical with the short staple or Georgian cotton, which is 

 remarkable for its large seeds being covered with short hairs or fuzz in addition to the 

 cotton. This is also the character of the New Orleans cotton which is said to have 

 been obtained from Mexican seed ; and this would appear to be the native country of 

 this species. If the fact were not supported by satisfactory evidence, it would be 

 difficult to believe that cultivation combined with change of soil and climate could 

 so completely alter the nature of the seed, at the same time that the staple became 

 both longer and finer. There maybe other species of Gossypium in Africa and China, 

 but we are without sufficient evidence on the subject, and the above appear to yield 

 all the commercial cottons. 



Dr. Royle then proceeded to observe that these cottons were produced in a great 

 variety of countries, from the line to 40° of north latitude, in very different soils, with 

 great diversity of climate and almost every variation in the mode of culture, and also 



