August 31, ign] 



NATURE 



3°; 



With llie exception of ihe crown, forehead, and lores, 

 which are iridescent violet, the general colour of the upper 

 [Kins is metallic-green. 



Paramaecium aurelia and P. caudatum are the subject 

 of several observations by L. Woodruff (Journ. of 

 Morphol., June; Journ. E.\pcr. Zoology, July; Proc. Soc. 

 Exper, Biology, viii.). He finds that these protozoa grow 

 well in a medium of beef extract, that the rate of repro- 

 auction in hay infusion is influenced by the volume of the 

 culture medium, and that the organisms excrete substances 

 which are toxic to themselves. The great majority of 

 individuals oi aurelia and caudatum can be distinguished 

 Both b) shape and by size, but the power of reproduction 

 of 1I1 two is practically identical. The macronucleus is 

 Subject to such variation that it affords no diagnostic 

 feature ; the micronuclear apparatus, on the other hand, 

 affords crucial diagnostic characters. 



A collection of six short papers is published in vol. 

 xiii., part x., of the Contributions from the United States 

 National Herbarium. A lichen contribution by Mr. 

 A. VV. C. Herre deals with the family Gyrophoraceaj in 

 California; the single species Umbilicaria semitensis, and 

 twelve species of Gyrophora, .'ire described. Some interest- 

 ing fai n noted by Mr. W. II. Brown as the result of 

 observations upon plant life in four shallow lakes in North 

 Carolina. Lake Ellis, the most fertile, is three miles long 

 wit li a maximum depth of 2 to 3 feet. Three zones of 

 vegetation are clearly distinguishable, dependent primarily 

 on substratum, not on depth of water, which is 

 fairly uniform. The central zone, underlaid by sand, 

 carries a sparse growth of Eriocaulon compressum 

 mingled with Eleocharis in shallower spots. The sub- 

 stratum becomes muddier in the intermediate zone, where 

 Vhilotria minor, Panicum hemitomon, and Eleocharis 

 picuous, and in the thicker sediment 

 of the marginal zone Eleocharis mutata, Castalia odorata, 

 grasses, and sedges are Hi- mosl prominent plants. 



As the conditions of the various regions of the United 

 State; cause marked vegetation differences, there is a 

 corresponding variety about the problems attacked by the 

 various agricultural experiment stations. Both at the 

 Connecticut ami Wisconsin stations, as well as elsewhere 



in ill- old settled reg . thi problem is to restore the 



ility of the soil consequent on many years of 

 griculture. Espei tally are some of the Wisconsin 

 clav soils deficient in phosphates, so that small dressings 

 ol rocl phosphate are producing unexpectedly large re- 

 turns. The management of sandy soils and of peat soils 

 is also receiving attention, and under Prof. Whitson's 

 some very useful work on soil improvement is 

 Being 1 arried out. Another direction is given to the work 

 at Connecticut. I onsiderable attention is being paid to 

 dairying and fruit-growing, both of which systems tend to 

 make the most of the soil and at the same time maintain 

 its fertility. A batch ol bulletins is recently to hand deal- 

 ing with the renovation ol old orchards and the planting 

 Of now ones, and with various dairy problems of practical 

 importance. 



The July number of The Cairo Scientific Journal contains 

 a preliminary note by Dr. W. Bean on the soils of the 

 Gezira. A large tract on the left bank of the Blue Nile 

 from Wad Mcdani to Kamlin is to be irrigated, and very 

 wiselj .1 thorough examination of the soil has been under- 

 taken, samples being collected down to a depth of more 

 than a metre along several lines across the area included in 

 me. The soils, both the more and the less fertile as 

 NO. 2183, VOL. 87] 



the natives classify them, are well supplied with potash 

 and phosphates, but, like most Egyptian and Sudan soils, 

 are markedly deficient in organic matter and nitrogen, so 

 that the results which may be obtained from their cultiva- 

 "i nill largely depend on their treatment with respect to 

 ibis deficiency. Rotation with a leguminous crop has not 



been used tost Sudan soils, but the experiment when 



made on ,1 small scale near Khartoum gave results exceeding 

 all expei 1 



The report of the Chemical Laboratories of the Survey 

 Department of Egypt is this year published separately. 

 Mr. A. Lucas, in discussing the work for 1910, reviews the 

 various stages by which the work has developed since its 

 commencement in iSqq. Almost all the work is done for 

 Government departments, and as approximately 40 per cent. 

 of tin- materials offered or delivered are found to be 

 adulterated or of very inferior quality, the laboratories 

 furnish a valuable safeguard on expenditure made. In spite 

 of this the importance of systematic analysis of supplies and 

 accurately drawn up specifications is only being slowly 

 realised, and the samples of material examined still bear 

 but a small proportion to the number which would represent 

 in adequate control of the supplies purchased. 



Is continuation of an earlier contribution dealing with 

 the AUioniaceae of the United States, Mr. P. C. Standley 

 bus prepared a synopsis of the Mexican and Central 

 American species of the family ordinarily known as the 

 Nyctaginaceae, that is published in the Contributions from 

 the United States National Herbarium (.vol. xiii., part xi.). 

 Twenty-two genera are differentiated, but some of these 

 an 1 hanges of name that are not sufficiently explained. 

 Among the nr.-w species are additions to Allionin, Boer- 

 haavia, Neea, and Pisonia. An interesting ubiquitous 

 is Pisonia aculeata, thai owes ii, distribution to 

 the viscid glands on the fruit. 



The prospects of viticulture in Rio Grande do Sul, the 

 southernmost State of Brazil, are discussed by Senor A. 

 de Azambuja in a pamphlet reprinted from articles in the 

 Gazeta do Commercio, published at Porto Allegre. The first 

 vine, introduced about sixty years ago, was the American 

 variety Isabella. Other American and some European 

 varieties were tried later, and the cultivation was taken 

 up by Italian colonists. Different varieties have been 

 grown with the object of discovering those suitable for 

 producing table fruit, wine, and currant grapes. In 

 recommending the' Isabella and other American varieties 

 I the labrusca species, the author claims that first-class 

 win.- out bi produced when the details of manufacture 

 an improved. 



A summary of Dr. Kienitz's important investigations into 

 the shapes and types of Finns sylvestris is provided by 

 Mi 1'.. Ribbentrop in the Transactions of the Royal 

 Scottish Arboricultural Society (vol. xxiv., part ii.). The 

 two 1 i" ue types are represented by the strong-branched, 

 broad-crowned tree common in Scotland, and the slender 

 pyramidal shape characteristic of the Baltic pine. Ihe 

 chief result of Dr. Kienitz's researches and experiments 

 lias been to demonstrate the heredity of special forms or 

 races, even when transferred to different conditions of 

 climate and soil, and thereby to prove the necessity for 

 getting the best and most suitable seed. It is noted that 

 nuch-branched tree is better fitted to hold its own 

 in the struggle for light, and is the prevailing form in 

 milder localities, whereas the slender form is developed 

 under more rigorous conditions, where heavy snowfalls 

 constitute a primary source of danger. 



