July i6, 1908J 



NA TURE 



253 



nrar Hllversham, also comes in for commendation. The 

 report concludes with a list of the antelopes seen by the 

 author in the course of his tour and one of those now 

 living in the Giza Gardens. Captain Flower, we notice, 

 uses the name Portax picta for the nilgai and Oreas canna 

 for the eland, thereby demonstrating that modern emenda- 

 tions in nomenclature are still by no means universally 

 accepted. 



We have also received a copy of the report of the Giza 

 Zoological Gardens for 1907, illustrated with a coloured 

 plan. The year appears to have been an unusually 

 successful one, the number of visitors and the amount of 

 money taken at the gates being in excess of any previous 

 season. Captain Flower directs special attention to the 

 circumstance that both kudu and addax have bred in the 

 menagerie. 



A FLORA of the Austrian Duchy of Styria, " Flora von 

 Steiermark," prepared by Dr. A. von Hayek, is announced 

 by the publishing firm of Gebriider Borntraeger. To the 

 special seclion-'consisting of an enumeration of the plants 

 will be added a general survey of plant distribution in the 

 duchy and in neighbouring coimtries. The work is to 

 appear in about eighteen monthly parts, each costing three 

 mafks. The first part contains the pteridophytes and a 

 few pages of the gymnosperms. The features of the work 

 are the analytical keys to the orders, genera and species, 

 brief diagnoses and localities for each genus and species, 

 and references to literature. Considerable interest attaches 

 to the flora, as certain ranges of the eastern Alps lie 

 within the province, and the vegetation in the lowlands 

 shows affinities with the flora of Illyria. 



.\ SHORT account — accompanied by excellent illustrations 

 — of the anatomical features of the extranuptial 

 nectaries of certain plants is contributed by Mr. K. Ono 

 to the Journal of the Roval College of Science, Tokyo 

 (vol. xxiii., article 3). On the ground of development, the 

 writer distinguishes two types of nectaries, those derived 

 from epidermal cells only, as in species of Polygonum, and 

 those derived from both hypodermal and epidermal cells. 

 It is staled that in some cases the secretion from the 

 glandular cells is forced into a space between them and 

 the cuticle, until finally the liquid escapes by rupture of 

 the cuticle ; in other cases it is believed that the secretion 

 permeates the cuticle. Physiological experiments indicated 

 that the secretion is mainly controlled by internal condi- 

 tions, and that of external factors moisture is the most 

 important. 



The idea has been mooted, and has met with some 

 measure of acceptance, that as agricultural land after a 

 repetition of crops of any given species becomes unsuited 

 to the requirements of that species, so, after a proportion- 

 atelv long period, on land bearing pure forest, the seedlings 

 of the crop may eventually fail owing to changes in the 

 properties of the soil. In this connection, Mr. B. O. 

 Coventry contributes an article on alternation of forest 

 crops to the June number of the Indian Forester. He 

 instances the observed failure of natural reproduction of 

 the blue pine, Pinus eAccisa, under its own cover with the 

 incursion of deodar, also the gradual extension of mulberry 

 into a Punjab plantation where originally " shisham," 

 Dalbergia sissoo, was dominant. In the North-West 

 Provinces, at a high level, it has been noted that Oucrctis 

 iiicana is invading the domain of Pinus longifolia, and 

 blue pine is advancing into the oak ; at another level, 

 Ouercus semicarfiifolia is losing ground to spruce and 

 silver fir. The subject is one that deserves the attention 

 of foresters. 



SO. 2020, VOL. 78] 



The attention of geologists may be profitably directed 

 to two important papers on the submarine stratigraphy of 

 the English Channel, published in the Journal of the 

 Marine Biological Association of the United Kingdom, vol. 

 viii., No. 2, in May of the present year. Mr. L. R. 

 Crawshay (p. 99) discusses the conditions under which the 

 stones and gravel on the Channel floor become exposed 

 by a constant drift of the fine material towards the English 

 coast. Mr. R. Hansford Worth contributes (pp. 1 18-188) 

 a critical review of a large number of specimens dredged 

 up by Mr. Crawshay on the S.S. Oithona in 1906, and 

 also describes those collected by previous observers, in- 

 cluding his own published work of 1899. The greatest 

 interest centres in the discovery of true chalk, in addition 

 to numerous flints, in the region south of the Eddystone. 

 Flints occur, indeed, in practically all the dredgings. One 

 block of foraminiferal limestone, with Miliolinas, clearly 

 of Eocene age, was found in mid-channel off the Lizard, 

 providing a valuable argument for those who view the 

 Parisian Calcaire grassier as having been deposited in a 

 sea spreading eastward from the Atlantic. Mr. Worth 

 brings his conclusions together in the form of an interest- 

 ing geological history of the depression which resulted in 

 the English Channel. 



In Meteorologische Zeitschrift for May, Dr. J. Hann 

 contributed an interesting paper on the problem of the 

 vertical distribution of sea temperature in the eastern 

 Mediterranean. He asks what conceivable physical process 

 would allow the surface temperature to penetrate to a depth 

 of about 500 metres, as has sometimes been assumed, in the 

 period of half a year ; the chief object of the paper is to 

 raise a discussion on this question. Dr. Hann thinks that 

 the lower limit of vertical circulation might be assumed to 

 be about 100 metres, and that we should then have to 

 distinguish between three different strata of temperature :— 

 (i) the superficial, to a depth of about 100 metres; (2) from 

 about 500 metres to the bottom, where the temperature is 

 nearly uniform (14° C. to i3°-5 C.) ; and (j) the intervening 

 space from, say, 100 to 500 metres. 



We have received vol. xlix., part ii., of the .Annals of 

 Harvard College Observatory, containing meteorological 

 observations at eight auxiliary stations in Peru for the 

 years 1S92-5 from records of self-registering instruments. 

 Although these records are not complete, especially at the 

 mountain stations, where the difficulties of carrying on 

 observations at such great altitudes are considerable, 

 meteorologists are much indebted to the authorities of the 

 college for this valuable contribution, which has been very 

 carefully prepared for publication by Prof. Bailey under 

 the direction of Prof. Pickering. In general, only the 

 hourly means and extreme values for each month are given, 

 but for the mountain stations individual readings are pub- 

 lished. The observations at .'\requipa for the same period 

 were contained in part i. (to which we have already re- 

 ferred), and the eye observations, with descriptions of the 

 stations and an account of the difficulties connected with 

 them, were given in vol. xxxix., parts i. and ii. 



Statistics issued by the Home Office show that the 

 total production of coal in the United Kingdom last year 

 was 267,830,962 tons, which is an increase of 16,763,334 

 tons over that of the previous year. The death-rate from 

 accidents of underground and surface workers as a whole 

 was 1-32 per 1000. 



The Marine Department of the Board of Trade has 

 issued a circular (No. 1443) dealing with the manufacture 

 and testing of steel. The instructions given are based on 

 the reports of the Engineering Standards Committee, and 

 deal with the testing of steel for use in boilers, plates, 



