4/2 



NA TURE 



[June i6, 1910 



Theriodontia of the Carnivora, and so on. The author 

 bases his theory mainly upon palaeontological evidence, but 

 the ordinary zoologist will find it difficult to believe that 

 such highly specialised mammalian features as the develop- 

 /nent of hair, the allantoic placenta, and the habit of 

 suckling the young have been evolved many times over, 

 and yet always in conjunction with one another. 



The third part of the second volume of Dr. J. W. 

 Spengel's " Ergcbnisse und Fortschritte der Zoologie " 

 contams two useful summaries. The first, by Mr. H. F. 

 Nierstrasz, deals with recent additions to our knowledge 

 of the Chitons, which has enormously increased during 

 recent years. The second, on the physiology of the facetted 

 eye, by Mr. Reinhard Demoll, is based almost entirely on 

 Exner's classical, but no longer very recent, work on the 

 compound eyes of crustaceans and insects. The problem 

 presented by these eyes is an extremely complex one, and 

 really lies in the domain of the student of physical optics 

 rather than that of the zoologist. On the whole, it appears 

 that the Miillerian theory as to their mode of action still 

 holds the field, but that this theory is not equally applicable 

 to all cases. 



REPORTS ON ICE IN SEAS AND OCEANS. 



'T'HE report on the state of the ice in the Arctic seas 

 during 1909, published by the Danish Meteorological 

 Institute, possesses more than usual interest on account 

 of .Admiral Peary's remarkable sledge journeys in the 

 spring of that year. It summarises the conditions for each 

 month, so far as known from reports supplied by traders 

 to those parts, with maps for April-August inclusive. The 

 state of the ice was unfavourable in Barents Sea and round 

 Spitsbergen, while in the Greenland Sea and Denmark 

 Strait the ice boundary was much more westerly than 

 usual. The coasts of Iceland were almost free of ice, but 

 much was observed off Newfoundland and on the Trans- 

 atlantic steamer routes. On the south-east of Greenland 

 and in the North American archipelago conditions were 

 very favourable ; in the Bering Sea they were about 

 normal, and in the Beaufort Sea rather favourable, especi- 

 ally towards the middle of the summer. It is inferred 

 that the amount of ice along the south-east of Greenland 

 will be somewhat small in 1910, and that favourable con- 

 ditions along the south-west coast of Greenland may result 

 during the summer of this year. 



From statements made on the useful monthly meteor- 

 ological charts for the North Atlantic and Indian Oceans 

 for April last, issued by authority of the Meteorological 

 Committee, it appears that ice was scarce in the Southern 

 Ocean during 1909. Up to about the middle of March 

 last reports of only forty bergs passed in that year were 

 received by the Meteorological Office ; half these related 

 to a position midway between New Zealand and Cape 

 Horn. A later chart, however, states that from December, 

 1909, they commenced to be rather frequently reported. 

 Tables referring to the bergs met with in previous 

 years show that lengths of six to thirty miles are not 

 uncommon, while some thirty of those sighted in that 

 ocean in the last quarter of a century were 800 feet or 

 above in height. Up to the present time, the report states, 

 the birthplace of the largest of the bergs (1000 to 1500 feet 

 in height) has not been definitely settled. 



THE INTERNATIONAL HORTICULTURAL 

 CONGRESS. 



T^HE International Horticultural Congress at Brussels, 

 April 30 to May 3, was attended by a large number 

 of representatives, including delegates from the important 

 horticultural societies. The meetings took place in the 

 Salle des F^tes in the grounds of the Great Exposition, at 

 that time in a very incomplete state. Among the various 

 subjects discussed was that of horticultural nomenclature. 

 While there has been a general desire on the part of the 

 more scientific horticulturists to conform to the rules of 

 botanical nomenclature agreed upon at the International 

 Botanical Congress at Vienna in 1905, it was felt that 

 certain details which were not discussed at Vienna, but 

 which were of special interest to horticulturists, should be 

 definitely settled. The congress was unanimous in agree- 

 •ng to adopt the Vienna rules of nomenclature, with neces- 



:-nO. 2120, VOL. 83] 



sary additions in the case of horticultural varieties iu.d 

 hybrids. It was agreed that the names of horticultural 

 varieties, expressed, in accordance with the rules, in the 

 vulgar tongue, must remain fixed when used in other 

 languages than the one in which they were originally 

 employed. When possible, the name should consist of a 

 single word, and never of more than two, or at most three, 

 words, 'io ensure valid publication a description of the 

 variety must be drawn up in Latin, English, French, 

 German, or Italian. 



As regards garden hybrids, it was agreed that the specific 

 name may be expressed in Latin, or in a vulgar tongue 

 and written in Roman characters ; if possible it should be 

 a single word, but, at any rate, not more than three 

 words. Various suggestions had been made as to the 

 system of nomenclature for artificial hybrids in which two, 

 three, or more genera are involved. In the case of bi- 

 generic hybrids, the general custom was confirmed of 

 forming a Latin generic name by the combination of the 

 names of the parents ; the specific name, also in Latin 

 form, is to be separated from the generic by the sign of 

 hvbridity, thus, LaeliocattleyaxSmithii. For plurigeneric 

 hybrids the recommendation of the Royal Horticultural 

 Society of London was adopted, namely, the use of a con- 

 ventional generic name, derived from that of some person 

 of distinction, with the termination ara, e.g. Lawrenceara. 



The programme of the congress also included a visit to 

 the Royal park and conservatories at Laeken, and to the 

 new colonial gardens and plant-houses. The latter con- 

 tain many plants of interest from the Congo. 



LOWELL OBSERVATORY PHOTOGRAPHS OF 



THE PLANETS.' 

 "T^HE pictures which I have the honour of showing to- 

 -*• night represent the results of the new planetary 

 photography originated at Flagstaff in 1903-5, and now 

 beginning to be successfully copied elsewhere, notably this 

 last summer by M. le Comte de la Baume Pluvinel and 

 M. Baldet in France, who from the summit of the Pic 

 du Midi de Bigorre succeeded themselves in getting 

 imprints of the canals of Mars. Although the method was 

 originally designed to exhibit the markings of what is 

 practically our nearest neighbour in space, it has since 

 been applied to the other planets with an outcome as sur- 

 prising as it is satisfactory. Little details which one 

 would not have supposed could sit still long enough for 

 their pictures to be taken stand out unmistakably on the 

 plates, the faint equatorial wisps of Jupiter offering a good 

 example of such tractability, though by no means the most 

 remarkable. 



That the canals of Mars should be made to write their 

 own signatures on a photographic plate was the occasion 

 of the invention of the process, which, after long and 

 patient study by my assistant, Mr. Lampland, they were 

 finally induced to do. To his marvellous feat the best 

 tribute was "that of Schiaparelli, who, after recognising 

 the canals on the print sent him, wrote me in wonder 

 that photography could be made to do such work, " I 

 would never have believed it possible." Since then further 

 improvement has been reached, to which almost every 

 member of the staff has contributed. The process is based 

 upon what our visual study of the planets has taught us 

 to be the crux in the matter — the all-importance of defini- 

 tion. For this reason the older celestial photography, 

 which furnishes such beautiful pictures of the stars and 

 nebulae, was here impotent. This will be realised when | 

 one considers that the whole disc of a planet could be put 

 inside the image of a single star. For a like cause re- 

 flectors cannot be employed, for with them all faults, 

 instrumental or atmospheric, are magnified three-fold over 

 those of a lens. They may give imposing-looking pictures, 

 but the finer detail is lost, a fact which is evident at once 

 to an expert. Now it is in the registration of this finer 

 detail that the accomplishment lies, and which from a 

 scientific point of view marks its importance. 



Study of the conditions leading to definition has made, 

 these photographs possible, just as lack of such study! 

 alone makes possible the scepticism one sometimes hears. 



1 A discourse delivered at the Royal Institution on Afril 8 by Prof. 

 Percival Lowell. 



