October io, 1907] 



NA TURE 



597 



on cocoa-nut diseases in Trinidad, describing a root disease 

 referred to a fungus Botryodiplodia, a leaf disease caused 

 by a Pestalozzia, and a bud-rot disease, is also published. 



The third part of the first volume of the Proceedings 

 of the Association of Economic Biologists is devoted to 

 the papers presented at the meeting of the society held 

 in Cambridge in January. The majority of the papers 

 are represented by abstract or title, but the paper by Mr. 

 E. S. Salmon on the American gooseberry-mildew is 

 printed at length. The author refers to the spread of 

 the disease, and its prevalence in parts of Worcestershire, 

 where the County Council has been taking measures to 

 stamp it out ; also he points out the necessity for establish- 

 ing a sub-department of the Board of .Agriculture to look 

 after the fruit industry. 



The latest number of the entomological series of 

 Memoirs of the Department of .Agriculture in India (vol. 

 i.. No. s), for which Mr. E. E. Green and Dr. H. H. 

 Mann are conjointly responsible, is devoted to the Coccida; 

 attacking the tea plant in India and Ceylon. .Although 

 thirty species are enumerated, only two or three have so 

 far proved serious pests, but it is stated that with 

 Coccids, even more than other phytophagous insects, 

 every species must be regarded as a potential enemy, since, 

 owing to some unforeseen change, dangerous multipli- 

 cation may ensue. Two new .species, Cliinnasftis manni, 

 Dactylopius theaecola, and a new variety of Tachardia 

 decorclla are described. 



CoM.MissiONED by the New Zealand Government to under- 

 take a botanical survey of the small island of Kapiti, 

 situated in Cook Straits, Dr. L. Cockayne has compiled 

 a highly interesting report describing the various plant 

 formations, and enumerating the indigenous ferns and 

 flowering plants. It is proposed to conserve the island 

 as a sanctuary for native birds and plants, espociallv for 

 species that are becoming rare. As a shelter for birds, and 

 from an ecological standpoint, the forests are alike 

 important. Corynocarpus laevigata, Dysoxylutii spcctabile, 

 Macropiper exceUum, Myoporum laetum, and Melicytus 

 ramiflorus are conspicuous trees. The northern rata, 

 Metrosidcros rohusta, varies greatly, sometimes throwing 

 out arches composed of aerial roots. Other species of 

 .Metrosideres generally form lianes, and among them 

 Mctrosideros scandens, but when growing in the open it 

 assumes a shrubby habit. .Allusion is also m.idi- to the 

 marked heterophylly of Lomaria filiformis, to the cauliflory 

 or production of flowers on the naked stems of several 

 trees, and to many other interesting ecological features. 



Under the title " Ombre sismiche e rimbalzi sismici," 

 Prof. \'. Monti has issued a pamphlet dealing wi;h the 

 phenomenon known as earthquake shadow. He finds that 

 Mount Etna appears to have a protective effect in the 

 case of earthquakes in Sicily, and that, wherever the 

 focus may be situated, places lying on the further side of 

 the mountain do not feel the shock, though others at a 

 greater distance are shaken. Monte Cimone, in northern 

 Italy, seems to e-xercise a similar protective effect, but the 

 much higher range of the Gran Sasso d'ltalia and Maiella 

 has no influence of this nature. He rejects the explan- 

 ation suggested by Prof. Rizzo in his study of the 

 Calabrian earthquake of September 8, 1905, but offers 

 none in its stead. We may remark that the term shadow 

 is based on the supposition that earthquakes originate in 

 areas of small dimensions compared to that over which 

 they are felt; the term loses its significance if Major 

 Harboe's suggestion of extended origins, noticed in Nature 

 of April 26, 1906, is accepted. 



NO. 1980, VOL. 76J 



The U.S. Monthly Weather Review for May contains a 

 full translation, by Dr. O. L. Fassig, research director 

 of Mount Weather Observatory, of M. G. Guilbert's 

 principles of forecasting the weather, submitted to the 

 international competition at Li^ge, organised in 1905 by 

 the Belgian Astronomical Society, with the view of show- 

 ing the state of our knowledge of that subject. The jury, 

 which was composed of six well-known meteorologists, 

 unanimously awarded the first prize to M. Guilbert, of 

 Caen, whose forecasts were based upon conclusions drawn 

 from the study of the relation of the theoretical to the 

 actual wind. He claims to be able to predict with pre- 

 cision the displacements and variations of centres of high 

 and low pressure for twenty-four hours in advance, and 

 to foretell the inception and dissolution of storms. Dr. 

 Fassig points out that the rules can readily be put to 

 test, and that the paper should receive the careful con- 

 sideration of all who make weather forecasts. The sub- 

 ject is referred to in the last Parliamentary Report of the 

 Meteorological Committee, and a valuable discussion of the 

 principles will be found in the Archives des Sciences for 

 July, 1906, by M. Brunhes, chairman of the jury of 

 award. 



Science for .August 30 contains the presidential address 

 of Mr. F. T. Shutt to the section of agricultural cheinistry 

 at the meeting of the American Chemical Society held 

 this summer in Toronto. Mr. Shutt's address deals inainly 

 with the virgin soils of the new north-west, showing by 

 analysis their richness in nitrogen, but pointing out how 

 rapidly they become exhausted under the common system 

 of growing successive wheat crops with an occasional bare 

 fallow. He gives figures to show that twenty years of 

 such cultivation has reduced the nitrogen content of the 

 soil down to the depth of 8 inches by no less than 

 220(1 lb. per acre, of which not more than 700 lb. has been 

 obtained in the crop. .Although no marked falling off in 

 the vield of this .soil is as yet apparent under proper culti- 

 vation, chemistry warns the cultivator that a great drop in 

 fertility must inevitably take place unless soinething is 

 done to replenish the nitrogen. This, Mr. Shutt points 

 out, can be done by the growth of clover, and gives 

 examples of the enrichment of the soil consequent upon 

 the introduction of this crop. 



Mr. Ch.arles a. Culver, of the University of Penn- 

 sylvania, has undertaken a study of the relative efficiencies 

 of the various types of receiving systeins in use in wire- 

 less telegraphy, and the Physical Review for September 

 contains an account of the first part of his investigations. 

 Of the types tested, those consisting of one or more 

 vertical wires are the most efficient, and it seems 

 immaterial whether the component parts arc connected 

 together at the lower, upper, or both ends. Partial screen- 

 ing of the aerial produces little effect, while the resist- 

 ance of the earth between the sending and receiving 

 stations is of prime importance. From a consideration of 

 his own results and those of others, Mr. Culver concludes 

 that the theory of propagation of the waves through the 

 surface of the earth accounts for more of the observed 

 facts than the free ether-wave theory, although it does 

 not at present account for several phenomr-na encountered 

 in practical work. 



RiCF'RiNT No. 40 from the Bulletin of the Bureau of 

 Standards at Washington consists of an account of some 

 preliminary measurements of the temperature and selective 

 radiation of the filaments of various kinds of incandescent 

 electric lamps mad,j by Messrs. C. W. Waidn'-r and G. K. 



