478 



NA TURE 



\_AIarck 15, 



sulphide, sulphone, and some other new bodies, the author 

 develops some general considerations on the homologous series 

 to which belong the heptylic sulphureted derived substances. 

 These considerations throw fresh light on the evolution of the 

 physical and chemical properties of compound bodies through 

 the various species of a common genus. Tlius it is shown that 

 the chemical character of the heptylic combinations must be 

 considered as the development of properties whose source or 

 origin is already found in the lower terms of the series of which 

 heptyl is a member. — A contribution to the study of the de- 

 velopment of the epiphysis and of the third eye in reptiles, by 

 M. Francotte. This third eye, of the invertebrate type, already 

 described by Graaf and Spencer, is here exhaustively studied in a 

 large number of reptilian embryos from the province of Namur, 

 in all of which it is very distinctly traced from the epiphysis at 

 the roof of the thalamencephalon to the complete development 

 of the pineal organ. In one species of lizard this eye passes 

 through a series of successive phases each realized in a permanent 

 way in one or other of the adult reptiles. But in all of them 

 the optic nerve has disappeared, which connected the organ with 

 the nerve-centres for a short time in the embryonic state. — This 

 number of the Bulletin contains an exhaustive memoir on the 

 fresh-water fishes of Belgium, by Baron Edm. de Selys Long- 

 champs. 



SOCIETIES AND ACADEMIES. 

 London. 



Royal Society, February 16. — "A new Method of deter- 

 termining the Number of Micro-organisms in Air." By Prof. 

 Carnelley, D.Sc, and Thos. Wilson, University College, Dundee. 

 Communicated by Sir Henry Roscoe, F. R.S. 



This is a modification of Hesse's well-known process. It 

 consists essentially in the substitution of a flat-bottomed conical 

 flask for a Hesse's tube. Its chief advantages are : (i) much 

 smaller -cost of flask and fittings as compared with Hesse's 

 tubes ; (2) very much fewer breakages during sterilization ; 

 (3) great economy in jelly ; (4) freedom from leakage during 

 sterilization ; (5) results not vitiated by aerial currents. 



" Notes on the Number of Micro-organisms in IMoorland Air." 

 By the same Authors. 



A number of determinations made last August "on the 

 heather" in the n^rth of Forfarshire show that the pure air 

 from the hills and moors far removed from towns was free from 

 Bacteria, but contained on the averao;e 3 '5 moulds per 10 litres 

 of air. In winter the number would be still less. 



Linnean Society, March i. — Mr. Carruthers, F. R.S., 

 President, in the chair. — An interesting collection of ferns from 

 the Yosemite Valley was exhibited by Mr. W, Ransom, who 

 also showed some admirable photographs of rare plants, many of 

 them of the natural size. — Mr. J. E. Harting exhibited a coloured 

 drawing, life-size, of a South American game bird (the Rufous 

 Tinamu) which has been successfully introduced into this 

 country at Brightlingsea, Essex, by Mr. J. Bateman, and made 

 some remarks on its affinities, pecuharities of structure, and 

 habits. In a discussion which followed Prof. Mivart, Mr. Christy, 

 and Mr. W. H. Hudson took part, the last-named giving some 

 account of the bird from personal observation of its habits in the 

 Argentine Republic. — The first paper of the evening was then 

 read by Mr. E. G. Baker on a new genus of Cytinace^e from 

 Madagascar. This curious plant, to which the author has given 

 the name of Botryocytinus, grows parasitically on the trunks of 

 a tree of the natural order Hamamelidece. Its nearest ally is 

 Cytimis, of which the best known species grows on the roots of 

 the Cistnses of the Mediterranean basin. The Madagascar plant 

 is without any stem, and the sessile flowers grow in clusters, 

 surrounded by an involucre. Each cluster is unisexual, and the 

 ovary is unicellular, with about a dozen parietal placentae and 

 innumerable minute ovules. It was discovered during a recent 

 exploration of the Sakalava country, by the Rev. R. Baron, of 

 the London Missionary Society. — The next paper, by Mr. J. F. 

 Cheeseman (communicated by Sir Joseph Hooker, F. R. S.), was 

 entitled "Notes on the Fauna and Flora of the Kermadec 

 Islands," and as regards the flora might be considered as supple- 

 mentary to a paper on the flora of these islands, published by 

 Sir Joseph Hooker more than twenty years ago (Journ. Linn. Soc, 

 1856). These islands, situated about 450 miles north-east of 



New Zealand, between that country and Fiji, were shown to be 

 of volcanic origin, with a fauna and flora resembling to a great 

 extent those of New Zealand. A few land birds were noted as 

 common to New Zealand ; and to the list of plants drawn up by 

 Sir Joseph Hooker, from collections made by Macgillivray, 

 several new species were added by Mr Cheeseman, chiefly ferns. 

 A. discussion followed, and in illustration of Mr. Cheeseman's 

 remarks, Mr. J. G. Baker exhibited specimens of a new endemic 

 Duvalia closely allied to the well-known D. canariensis of the 

 Canary Islands and Madeira. 



Geological Society, February 17.— Annual Genera] Meet- 

 ing. — Prof. J. W. Judd, F. R.S., President, in the chair. — The 

 Secretaries read the Reports of the Council and of the Library 

 and Museum Committee for the year 18S7. The President pre- 

 sented the Wollaston Gold Medal to Mr. Henry Benedict 

 Medlicott, F.R.S. He also handed to Dr. Archibald Geikie 

 the balance of the proceeds of the Wollaston Donation Fund for 

 transmission to Mr. John Home, and the Murchison Medal for 

 transmission to Prof. J. S. Newberry. The balance of the pro- 

 ceeds of the Murchison Geological Fund was handed to Dr. 

 Henry Woodward for transmission to Mr. Edward Wilson ; and 

 the President presented the Lyell Medal to Prof. H. Alleyne 

 Nicholson, one moiety of the balance of the proceeds of the 

 Lyell Geological Fund to Mr. Arthur Humphreys Foord, and 

 the second moiety of the balance of the proceeds of the Lyell 

 Geological Fund to Mr. Thomas Roberts. ' The President then 

 read his Anniversary Address, which we have already printed. — 

 The ballot for the Council and Oflicers was taken, and the 

 following were duly elected for the ensuing year : — President : 

 W. T. Blanford, F.R.S. Vice-Presidents : John Evans, F.R.S. ; 

 Prof. T. McKenny Hughes ; Prof. ]. Prestwich, F.R.S. ; Henry 

 Woodward, F.R.S. Secretaries : "W. H. Hadleston, F.R.S. ; 

 ]. E. Marr. Foreign Secretary : Sir Warington W. Smyth, 

 F.R.S. Treasurer: Prof. T. Wiltshire. Council: W. T. 

 Blanford, F.R.S.; John Evans, F.R.S.; L. Fletcher; A. 

 Geikie, F.R.S. ; Henry Hicks, F.R.S. ; Rev. Edwin Hill ; W. 

 H. Hudleston, F.R.S.; J. W. Hulke, F.R.S.; Prof. T. 

 McKenny Hughes ; Prof. T. Rupert Jones, F.R.S.; Prof. J. 

 W. Judd, F.R.S. ; R. Lydekker ; Lieut.-Col. C. A. McMahon ; 

 J. E. Marr ; E. T. Newton ; Prof. J. Prestwich, F. R. S. ; Prof. 

 H. G. Seeley, F.R.S. ; Sir Warington W. Symth, F.R.S. ; W. 

 Topley ; Rev. G. F. Whidborne ; Prof. T. Wiltshire ; Rev. H. 

 H. Winwojd ; Henry Woodward, F. K.S. 



February 29.— W. T. Blanford, F.R.S., President, in the 

 chair. — The following communications were read : — An estimate 

 of post-Glacial time, by T. Mellard Reade. The _author 

 showed that there exists on the co.asts of Lancashire and 

 Cheshire an important series of past- Glacial deposits which he 

 has studied for many years. The whole country to which his 

 'notes refer was formerly covered with a mantle of low-level 

 marine boulder-clay and sands, and the valleys of the Dee, 

 Mersey, and Ribble were at one time filled with these Glacial 

 deposits. These Glacial beds have been much denuded, especially 

 in the valleys, where the rivers have cleared them out, in some 

 cases, to the bed rock. Most of this denudation occurred dur- 

 ing a period of elevation succeeding the deposition of the low- 

 level boulder-clay. On this eroded surface and in the eroded 

 channels lie a series'of post-Glacial beds of a most interesting and 

 extensive nature. They consist of estuarine silt and So-ohictdaria 

 clay covered by extensive peat-deposits, containing the stools of 

 trees rooted into them. Upon these lie, in some places, recent 

 tidal silts, and on the coast margin blown sand and sand dunes. 

 The series of events represented by the denudation of the low- 

 level boulder-clay and the laying down of these deposits is as 

 follows : — (i) Elevation succeeding the Glacial period, during 

 which time the boulder-clay was deeply denuded in the valleys. 

 (2) Subsidence to about the 25 feet contour, when the estuarine 

 silts and clays were laid down. (3) Re-elevation, representing 

 most probably a continental connection with the British Isles, 

 during which time the climate was milder than at present, and 

 big trees flourished where now they will not grow. (4) Sub- 

 sidence to the present level, the submersion of the peat and 

 forest-beds, the laying down of tidal silt upon them, and the 

 accumulation of blown sand along the sea-margin extending to a 

 considerable distance in an inland direction. It was estimated, 

 from a variety of considerations, that these events, all posterior 

 to the Glacial period, represent a lapse of time of not less than 

 57,500 years, allotted as follows : 40,000 years for the elevation 

 succeeding the Glacial period, measured by the denudation of the 



