I 12 



NATURE 



[April ii, 191 8 



and May." Having regard to the importance of the 

 sturgeon as a "food-fish," it would seem well worth 

 while to afford the protection suggested by Prof. D'Arcy 

 Thompson in this brief but valuable survey. 



A VERY welcome insight into the life-history of the 

 little penguin (Eudyptula minor) is afforded us by Dr. 

 Brooke Nicholls in the Emu — the official organ of the 

 Royal Australasian Ornithologists' Union — for Janu- 

 ary. Dr. Nicholls 's shrewd observations have added 

 much to our knovi^-ledge of the habits of these noc- 

 turnal birds. He has also told us much in 

 regard to their food, moulting, the coloration of the 

 soft parts, and the dififerences between the sexes, which 

 are closely alike. His observations were made on 

 Philip Island and neighbouring stacks. He comes to 

 the conclusion, in spite of statements to the con- 

 trary, that there is but one species of little penguin on 

 Philip Island, and expresses regret that these 

 birds are "not found upon the list of our protected 

 birds." The need for this step, he points out, is 

 urgent, since they are now threatened by increasing 

 settlement, and, besides, are largely used as bait by 

 fishermen for their lobster-pots. 



The special Committee appointed by the Board of 

 Agriculture, Trinidad, to inquire into the present posi- 

 tion and prospects of rubber cultivation in the island 

 has recently published its report in the Bulletin of the 

 Department of Agriculture, vol. xvi., part 3. The 

 report is a very interesting and valuable document, 

 tracing the history of the industry from the year 1876, 

 when two plants of Hevea brasiliensis , the Para rubber, 

 were sent from Kew to Trinidad. The report is based 

 on returns sent in from estates, but as several replies 

 have not yet been received the total acreage under rubber 

 qannot be given. From the returns received there are 

 found to be 130,593 trees of Hevea, 81,975 of Castilloa, 

 and 45,000 of Funtumia. The return for Castilloa 

 should be much higher, as owing to the highly favour- 

 able views entertained as to this plant it was very 

 largely planted in the colony. Experience has shown, 

 however, that this Central American rubber tree is far 

 inferior in every way to Para rubber as a plantation 

 tree, and much of the work done in Trinidad must 

 be regarded as a failure. On many estates Castilloa 

 has now been removed, and a good deal of rubber 

 land is derelict. The Committee points out that there 

 is a good deal of land in Trinidad suitable for Hevea 

 cultivation, and the report indicates clearly the proper 

 lines on which planting should be undertaken and the 

 returns which may be anticipated. The report ends 

 with a summary of recommendations, in which the 

 Committee states that, while cacao, sugar, and 

 coconuts hold first place, Hevea should certainly rank 

 in the front line of the secondary industries, such as 

 limes, rice, and coffee. It is also pointed out that 

 coffee may be interplanted with Hevea. Two impor- 

 tant recommendations relate to the need for co-opera- 

 tion among rubber growers, and the formation of a 

 Rubber Planters' Association, either on lines similar 

 to those of, or in amalgamation with, the present 

 Cocoa Planters' Association. 



The Advisory Council of Science and Industry of the 

 Commonwealth of Australia has recently issued a 

 bulletin upon "The Factors Influencing Gold Deposi- 

 tion in the Bendigo Goldfield. " This goldfield is 

 famous for the very exceptional character of its reefs 

 of auriferous quartz, which are either bedded reefs, 

 subdivided into saddle reefs, trough reefs, and leg 

 reefs, or fault reefs or spurs. A large number of data 

 concerning these reefs has been collected, but the in- 

 ferences that can be drawn from these have not, so 

 far, proved very helpful to the prospector. It is 



NO. 2528, VOL. lOl] 



pointed out that the various dykes are geologically 

 younger than the quartz reefs, and can have played 

 no part in their origin, which is probably to be referred 

 to the intrusion of the granodiorite in Lower Devonian 

 times. Mineral solutions connected with this intru- 

 sion have been injected under pressure and have pro- 

 duced the reefs, in the case of saddle reefs mainly by 

 the filling of fissures, in the case of the other types 

 of deposit, mainly by replacement. The gold in the 

 reefs is principally concentrated on the walls, and its 

 distribution is never uniform along the reefs. Whilst 

 " the replacement origin of the reefs provides a possible 

 explanation for the gold shoots," it has to be admitted 

 that "some additional factors, at present unknown or 

 only guessed at, must influence the localisation of the 

 shoots"; in other words, science has not yet pro- 

 gressed far beyond the old Cornishman's "Where she 

 be, there she be " ! 



A NOVEL method of investigating the variation of the 

 germicidal action, of ultra-violet light with wave-length 

 has recently been described in the Proceedings of the 

 Royal Society, series B, vol. xc, by Drs. C. H. Brown- 

 ing and S. Russ. The method consists in photo- 

 graphing the ultra-violet spectrum on plates covered 

 with a film of gelatine or agar-agar inoculated with 

 micro-organisms instead of on an ordinary photographic 

 plate. After suitable exposure these plates are incu- 

 bated, and the action of the radiation is thereby ren- 

 dered visible ; those parts affected by the radiation 

 remain transparent, while the remaining parts become 

 opaque owing to the copious growth of the organisms 

 which were not destroyed by the action of the rays. 

 The region of activity of the radiation is between the 

 wave-lengths 2960 and 2100 A.U., with a maximum in 

 the region 2800 to 2540 A.U. ; the rays are, however, 

 easily absorbed by o-i mm. of skin, so that this type of 

 radiation can only be effectual in dealing with organisms 

 on the surface of a wound. Tne range of suscepti- 

 bility varies slightly for different organisms, but not 

 sufficiently so to provide a means of differentiating 

 between several kinds. 



An account of the optical stores captured from the 

 enemy, which were exhibited and described to the 

 Optical Society in November by Lt.-Col. A. C. Wil- 

 liams, is given in the November issue of the Trans- 

 actions of the society. The collection is fairly repre- 

 sentative, and includes range-finders, directors for field 

 and heavy artillery, dual sights, clinometers, sighting" 

 arcs, stereoscopic telescopes, periscopes, and sighting 

 telescopes for machine-guns. Col. Williams pointed 

 out how they all showed evidence of careful design and 

 high-class workmanship, how lacquer had been dis- 

 carded in favour of a tough, well-stoved enamel, and 

 how in many cases the instruments had been painted 

 after completion in order to cover all screws and render 

 the instruments waterproof. Single complex prisms 

 have been substituted for double reflecting prisms in 

 order to diminish the loss of light and to facilitate 

 adjustment. The balsaming of prisms together was 

 well done, and the balsam very hard. From the dis- 

 cussion which followed the exhibition it appeared that 

 while there was no new principle involved in the 

 instruments captured, the working out of the details 

 showed evidence of great care, and would repay study 

 on the part of British instrument-makers. The instru- 

 ments may be examined by permission of Prof. F. J. 

 Cheshire, Imperial College of Science, South Kensing- 

 ton. 



A LONG paper by Prof. Palazzo, chief of the Italian 

 Meteorological Service, discussing magnetic observa- 

 tions taken at Theodosia, in the Crimea, between 

 August 17 and 28, 19 14, appears in the Memorie delta 

 Societa degli Spettroscopisti Italiani (vol. vi., 1917)- 



