6o 



NA TURE 



[May 19, i<i92 



interferes with the continuity of the oceanic deposits, it 

 is abundantly clear from numerous sections that they rest 

 unconformably upon the Scotland series, and are as 

 distinct in respect of age as they are in respect of litho- 

 logical composition, and a greater contrast in all respects 

 can hardly be imagined than these two formations 

 present. 



The oceanic series is more than 300 feet thick, and is 

 divisible into five portions, which, however, blend into 

 one another. These are, in descending order — 



(i) Grey siliceous mudstones, consisting chiefly of fine 

 volcanic dust, with a few fragments of siliceous organisms. 



(2) Very fine-grained argillaceous earths, often red or 

 pink, but sometimes yellow or buff ; these are analogous 

 to modern oceanic " red clays." 



(3) Pulverulent chalky marls and earths, being consoli- 

 dated foraminiferal oozes passing down into calcareo- 

 siliceous earth with Radiolaria ; proportion of carbonate 

 of lime, 80 to 44 per cent. 



(4; Siliceous Radiolarian earth, consisting mainly of 

 Radiolaria, with sponge spicules and Diatoms, and a small 

 amount of fine calcareous matter. 



(5) Calcareo-siliceous earths, with 25 to 40 per cent, 

 of carbonate of lime passing down into purer chalky 

 €arth, with 60 to 80 per cent., which is in some places 

 converted into limestone by the infiltration of calcite. 



There is a considerable variation in the amount of 

 chalky matter even on what appears to be the same 

 horizon, and within short distances. The whole series is 

 more calcareous in the northern than in the southern 

 part of the island. 



Interstratified layers of volcanic sand and dust occur 

 at several horizons, some of them being light grey 

 pumiceous and felspathic sand, and others a mixture of 

 such material with Radiolarian earth stained brown by 

 what seems to be petroleum. 



With respect to organic remains, the calcareous earths 

 have yielded Foraminifera in abundance, a preliminary 

 examination of six samples by the late Dr. H. B. Brady 

 resulting in the discovery of 81 species. The siliceous 

 earths have furnished the specimen of Cystechinus crassus 

 recently described by Mr. J. W. Gregory, and they abound 

 in Radiolaria, as is very well known. Certain marls and 

 limestones on Bissex Hill prove to consist mainly of 

 Globigerina. 



The bearing of these fossils is discussed with regard to 

 (i) the age, (2) the conditions of depth, at which the 

 deposits were formed. The age is Pliocene, or Pleisto- 

 cene, while stratigraphical considerations make it most 

 probable that they are of Pliocene date. 



The depth of water indicated by the Foraminifera is 

 from 500 to 1000 fathoms, according to Dr. Brady. The 

 Cystechinus is considered by Mr. Gregory as strong 

 evidence for a depth of over 1000 fathoms, and is quite 

 consistent with a depth of over 2000 ; while the Radio- 

 laria are, in Prof Haeckel's opinion, most nearly allied to 

 those which occur in the deepest parts of modern oceans, 

 i.e. about 3000 fathoms. 



The coloured clays are remarkable for the almost com- 

 plete absence of carbonate of lime ; they correspond in 

 all essential points to those modern argillaceous oozes 

 which occur at from 2500 to 3000 fathoms, and have little 

 or no carbonate of lime. 



The available evidence points to the conclusion that 

 the depth of water varied from 1000 to 2500 fathoms, 

 and there may have been two epochs at which it was over 

 2000 fathoms. 



Radiolarian deposits have for some years been known 

 to exist in Trinidad, and the authors, having obtained 

 samples, are able to announce that these closely resemble 

 the Barbadian earths in general aspect, .in chemical 

 composition, and in microscopical structure. Similar 

 earths also appear to exist in Hayti. 



Finally, they di=cuss the changes in physical geography 



NO. 1 1 77, VOL. 46] 



which are indicated by the existence of these deposits, 

 and their probable equivalent in part of the white lime- 

 stone of Jamaica ; and they infer that the whole Central 

 American and Caribbean region was deeply submerged 

 during the Pliocene period, and that during this time 

 there was open and free communication between the 

 Atlantic and Pacific Oceans. The separation of the two 

 oceans, and the deflection of the Gulf Stream, were 

 changes accomplished by the upheaval of which evidence 

 was adduced in a former paper, and this upheaval is a 

 comparatively recent event. 



The minute structure of the rocks is described in 

 reports presented by Mr. W. Hill and Miss C. A. Raisin ; 

 the former showing that the Barbados chalk is similar in 

 all essential points to the Chalk of England. 



EDUARD VON KEGEL. 

 T^HE learned and genial Director of the St. Petersburg 

 ■*• Botanic Garden, Dr. Eduard von Regel, died 

 on April 27, in his seventy-seventh year. He was 

 the son of a Gotha parson, and developed a taste for 

 gardening while still quite young. During the hours 

 that might have been given to play he was usually en- 

 gaged at his favourite pursuit in his father's garden. 

 After the usual course of education, he spent several 

 years in various botanic gardens, and about 1842 he was 

 appointed " Obergartner " in the Botanic Garden at 

 Zurich. Here, in conjunction with Dr. O. Heer, the 

 celebrated palaeontologist, one of whose daughters he 

 subsequently married, he at once founded a Swiss journal 

 for agriculture and horticulture, and was exceedingly 

 active in promoting horticulture, both in writing and 

 practically. In 1852 he founded the now well-known and 

 still flourishing Gartenflora, which, however, he ceased 

 to edit after 1885. He soon gained fame, and when the 

 important post of Scientific Director of the St. Peters- 

 burg Botanic Garden became vacant in 1855, it was 

 offered to and accepted by Regel, and held by him to 

 the last. There he found a wide field for his energy and 

 abilities : but although he accomplished much meri- 

 torious botanical work, Russia is far more indebted to 

 him for the improvements he effected in horticulture 

 generally than for his botany. At the time when he first 

 went to St. Petersburg, gardening was at a very low 

 ebb, and the vast strides that have since been made in 

 this industry are very largely due to his untiring efforts. 

 He wrote treatises, introduced superior varieties of fruits, 

 vegetables, and flowers, and succeeded in gaining the 

 influence and support of exalted persons for his projects 

 both botanical and horticultural. It was mainly through 

 his exertions, we believe, that the first flower-show was 

 held in St. Petersburg. This was in 1858, and now 

 such a thing is no uncommon event. He was also in- 

 strumental in getting botanists attached to the Russian 

 exploring expeditions in Central and Eastern Asia, 

 whereby the gardens and herbaria, not only of Russia, 

 but of Europe, have been greatly enriched, and botanical 

 science advanced. Regel himself elaborated many of 

 the dried collections thus obtained, besides describing 

 a large number of plants cultivated in the garden from 

 seeds or bulbs sent thither by various travellers. One of 

 the best of his numerous writings is a monograph of the 

 genus Allium — " Alliorum adhuc cognitorum Mono- 

 graphia," — the number of species described exceeding 

 250, including a large number previously undescribed, the 

 fruits of the explorations in Asia. He was also joint 

 author of an enumeration of the plants collected in 

 Siberia by Semenoff, Radde, Stubendorft", and others. 

 Although gradually declining in health during the last 

 year or so, he continued to discharge the duties of his 

 office ; and although not so active with his pen as 

 . formerly, he contributed some descriptions of new plants 



