July- 4, 1895] 



NATURE 



market in one form or another, that it is considerably freer from 

 microhes than ordinary butter when the latter is not made with 

 Pasteurised cream. \\Tiereas butter contains an average of from 



10 to 20 millions of microbes per grm. , margarine-butter yields 

 but from 4 to 6 millions ; moreover, whilst in extreme cases as 

 many as 47 millions of microbes have been found per grm. 

 in butter, margarine can only boast of at most something over 



11 millions. Cold appears to act more prejudicially on 

 margarine microbes than it does on butter germs ; thus in one 

 case a reduction from 6i millions to 230,200 per grm. was 

 observe<l in margarine, whilst a similar exposure never succeeds 

 in eliminating more than one-third of those present in butter, 

 according to Lafar. It is reassuring to learn that in none of the 

 numerous samples examined were pathogenic bacteria dis- 

 covered ; many of the ordinary microbes present were isolated 

 and described, and amongst these two were found which the 

 authors believe are closely associated with rancid processes which 

 occur in old samples of margarine. To further reduce the 

 microbial population of margarine butter, it is suggested that 

 only .sterile milk and sterile water should be used in its manu- 

 facture from oleo-margarine, which is considerably poorer in 

 bacterial life than the finished product. 



I.N the years 1891 and 1892, the Norwegian Government fitted 

 out a vessel for the purpose of making temperature observations 

 round the Lofoden Islands, with the view of tracing the con- 

 nection between the habits of the cod and the temperature of the 

 water, and the Parliament voted a sum of money for the pur- 

 chase of thermometers for registering the temperature at various 

 depths. We have received from Lieutenant G. Gade, who was 

 entrusted with the investigation, a pamphlet entitled " Tempera- 

 turmaalinger i Lofoten," which contains an inlieresting account 

 of the results obtained. He found that at the same places the 

 temperature sometimes increased regularly according to the 

 depth, while at others there were two distinct strata of water, 

 the cold being uppermost. .-Vlthough the vertical variations of 

 temperature may have been considerable, yet he always found 

 an increase with depth. The favourite temperature of the cod 

 is supposed to be 5°C.,and while in January 1892 this was 

 found at the surface, in March 1891 it was only found al a depth 

 of 160 metres ; the greatest depth at which fishing takes place 

 is 200 metres, where 6°-7° C. were recorded nearly constantly 

 from Januar,' to the middle of April. Lieutenant Gade found 

 that when there were two strata of water, one cold(2°-3°C.) 

 uppermost, and one warmer (5°- 7° C. ) below, the cod was 

 always found in the warmer stratum ; but, as the fishing takes 

 place al depths where the temperature is from 4°-7° C. or more 

 (and the depths where these temperatures are found are very 

 different), the author considers that the fisherman cannot derive 

 practical advantage from temperature obsen'ations alone. 



Chorisis, or the doubling of the parts, is by no means a rare 

 occurrence in flowers. In this jAenomenon there appear, 

 apparently in the place of one floral leaf, especially a stamen, 

 two such Ic-ives either collaterally, i.e. beside one another, or 

 serially, above one another. These pairs of leaves may arise 

 either out of a single common primordiuin, or directly from the 

 axis. Up to the publication of a paper on " Das Reductions- 

 ge-setzder Blilthen," by Dr. Lad. J. Celakovsky (Stzb. derkiinigl. 

 bohnii.schan Ges. der Wissenschaften), morphologists agreed 

 in regarding chorisis as the division or branching of an originally 

 simple leaf. Dr. Celakovsky, however, comes to the following 

 conclusions, amongst others, after a very com])lete consideration 

 of a large number of instances. Normal chorisis occurs not as 

 a division of a single leaf, but rather as a fusion, or at least an 

 approximation of distinct and originally uniformly separated 

 leaves. In the ontogeny of the plant this may occur as a 

 branching or positive chorisis, as he terms it, of a single 

 NO. 1340, VOL. 52] 



primordium, but this fact does not afford, according to him, a 

 clue to the steps in the phylogenetic development, by which the 

 present state has come about ; but he believes, in opposition to 

 the hitherto received opinion, that the present condition in 

 these flowers was attained by negative chorisis or approximation. 

 Normal chorisis is the expression of an incomplete transition 

 from a state in which the indivi<lual leaves composing a whorl or 

 whorls were more numerous, into one in which they are less 

 numerous. It is, in fact, the resultant of two tendencies — one, the 

 older, to polymerism, and the other and newer, to oligomerisni. 

 The reduction so effected is always governed by the la« of the 

 alternation of the, consecutive leaf-whorls. Dr. Celakovski^s 

 paper is one of great interest, and the discussion as to the 

 origin of the various types of andrrecium will no doubt be 

 specially useful to those who are interested in the affinities of 

 the natural orders of dicotyledons and monocotyledons. 



The publishers of Knowledge announce that Dr. Isaac 

 Roberts, F. K.S., will shortly continue in that magazine his 

 selection of photographs of stars, star-clusters, and nebula;. 

 The series is intended to be in continuation of Dr. Roberts's 

 work, " A Selection of Photographs of Stars, Star-Clusters, 

 and Nebula," recently published, and which has contributed 

 very largely to the extension of the knowledge of astronomical 

 phenomena. 



The July number of Natural Science is devoted to brief 

 descriptions of the results of the Challenger Expedition, from 

 the points of view of investigations in many branches of know- 

 ledge. Each of the contributors, all of whom write with 

 authority upon their respective subjects, more or less confines 

 himself to answering the question, " How has the Challenger 

 Expedition advanced science?" The brief summaries thus 

 obtained form a very valuable and compact index to the advances 

 in various fields of natural knowledge due to the Expedition. 



The additions to the Zoological Society's Gardens during the 

 past week include a Bonnet Monkey (Macaciis simcus, 9 ) from 

 India, presented by Mr. John Norbury, Junr. ; a Macaque 

 Monkey (Macaciis cynomolgus, i ) from India, presented by 

 Mr. 11. W. Ball ; a Black-eared Marmoset (Hapale pencillala) 

 from South-east Brazil, presented by Mr. H. P. Roberts ; a 

 Rough Fox {Canis rudis) from British Guiana, presented by Dr. 

 Irvine K. Reid ; a Grey Ichneumon (Herpestes griseus) from 

 India, presented by Lady Champion de Crespigny ; seven 

 Black Salamanders (Salamandra atra), a Slowworm {.Anguis 

 fragilis) from .Switzerland, presented by the Rev J. W. 

 Horsley ; a Burchells Zebra (Eijiius burchelli, <J ) from South 

 Africa, a Common Rhea ( AV/ta americana) from South America, 

 deposited ; two Black-necked Swans (Cygniis nigricollis) from 

 .\ntarctic America, three Blue Snow Geese (Chen cariilescens) 

 from Alaska, purchased; a Thar (Capra jeinlaica,9 ), born in 

 the Gardens. 



OUJ? ASTRONOMICAL COLUMN. 



Variable Stars. — Dr. Chandler has completed a revised 

 supplement to his well-known second catalogue of variable 

 stars ; together they furnish a complete list of known variables, 

 comprising in all 344 stars. Some little difiiculty has been ex- 

 perienced in connection with the southern variables, on account 

 of the want of accurate positions and certain identifications in 

 some cases. Dr. Chandler especially shows a want of confidence 

 in the data relating to the variables discovered photographically 

 at the Boyden station of the Harvard College Observatory at 

 Arequipa, ; but considering the pressing need of a definitive 

 nomenclature, and relying on the assurances of Prof. Pickering, 

 most of these objects have been included in the catalogue and 

 letters assigned to them. 



All the recent observations made by the South .\frican ob- 



