November 24, 1910] 



NATURE 



1 1 



has an exceptional value to the students of the group, 

 more particularly since the U.S. National Museum 

 possesses, so far as the author could ascertain, about one- 

 fourth of the whole available material. Of the genera 

 "' =oplodon, Ziphius, and Berardius, Mr. True could find 

 rds of only about one hundred specimens in collections, 

 01 which more than half belong to the first genus, 

 Berardius being known only by about fourteen examples. 

 The most important addition to our knowledge of the 

 group in recent years was the discovery of representatives 

 of all three genera at Bering Island by Dr. Stejneger, 

 two of these being regarded as distinct species, one of 

 which was named in 1883 and the other in 1885. About 

 six vears ago it was ascertained that the range of the 

 Bering Sea forms extends to the eastern North Pacific. 

 After a descriptive catalogue of the specimens in the 

 Washington Museum, with notices of some examples in 

 other American collections, the author concludes his 

 memoir with a list of the recognisable existing species of 

 the group. Inclusive of the two representatives of 

 Hvperoodon, this list embraces thirteen species. 



The November number of the Quarterly Journal of 

 Microscopical Science (vol. Iv., part iv.) contains a very 

 interesting paper by Miss Muriel Robertson and Prof. 

 E. A. Minchin on the division of the collar-cells of the 

 calcareous sponge Clathrina coriacea. It appears that 

 these cells multiply by longitudinal fission, the division of 

 the nucleus being accompanied by a typical mitosis. The 

 chief interest attaches to the behaviour of the " blepharo- 

 plast " in this process. In the resting cell this organ 

 appears as a " basal granule " in connection with the 

 flagellum ; in mitosis it behaves as a typical " centro- 

 some," dividing into two parts, which cave to lie at 

 opposite poles of the nuclear spindle. Each of these 

 daughter centrosomes becomes the blepharoplast of one of 

 the daughter cells, and a new flagellum grows out from it. 

 Around each new flagellum a new collar develops, the old 

 collar and flagellum of the mother cell completely dis- 

 appearing. The authors discuss the bearing of these facts 

 upon the vexed question of the interpretation of the 

 " kinetonucleus " in trjpanosomes, and conclude that the 

 latter is a true nuclear body, and not a blepharoplast or 

 centrosome. 



The destruction of agricultural plant pests by chemical 

 means is reviewed by Mr. H. C. Long in Knowledge 

 I (November). The practice is based on direct experiment, 

 as plants differ considerably in their resistance to chemical 

 solutions ; thus charlock and dandelions are readily attacked 

 ] by a copper sulphate solution, while Cnicus an-ensis and 

 I clover are much more resistant. According to BoUey, 

 , shepherd's purse, Camellina saliva, chickweed, corn-cockle, 

 ! bindweed, and plantain are all amenable to chemical treat- 

 ment, whereas sow-thistle, Bromus secalinus, wild oats, 

 ; and couch grass cannot be effectively controlled. The 

 I author directs attention to the desirability- of carrying out 

 I systematised experiments in different parts of the country. 



•An account of the Arnold Arboretum, well known by 



name to British botanists, is contributed by Mr. W. J. 



Bean to the Kew Bulletin (No. 8). Situated in a suburb 



of Boston, U.S.A., and extending over 200 acres, it is 



noted for the large collection of trees and shrubs in which 



north-east American and north Asiatic species predominate. 



marked feature in the arboretum is the ground cover of 



nrubs in place of grass around the trees; various species 



j of Vaccinium, Aster, Rubus, and other native shrubs are 



grown in this way. Mr. Bean pays a warm tribute to 



e energetic director. Prof. C. S. Sargent, for the excel- 



NO. 2143, VOL. 85] 



lent work that is being carried on; one of his greatest 

 tasks has been the elucidation of North American species 

 of Crataegus, of which specimens from type plants occupy 

 15 acres. A monumental work was provided by the " Silva 

 of North America," in fourteen volumes, and another 

 massive publication that will shortly appear is a biblio- 

 graphy of trees and shrubs of the world. Incidentally, the 

 Bulletin contains evidence of cordial cooperation between 

 Prof. Sargent and Kew in the publication of a list of new 

 species of Impatiens from China, forwarded to Sir Joseph 

 Hooker by Prof. Sargent for description. 



The report of the chief inspector of mines of the 

 native State of Mysore for the year 1908 has just been 

 issued, and affords satisfactory evidence that mining opera- 

 tions are being conducted here with energy and skill as 

 well as with due attention to the safety of those engaged 

 in the work. A small amount of manganese and chrome 

 ore is being raised, but the principal mining operations 

 are, as heretofore, confined to the Kolar goldfield. The 

 report shows that there were ten companies at work, of 

 which seven were producing gold, the value of the bullion 

 produced being just over 2,000,000/. sterling, or almost 

 exactly the same as in the previous year. The quartz 

 raised contains gold to the value of just about 3/. per ton, 

 the working costs amounting to about one-half of this 

 figure. Elaborate tables are attached to the report, those re- 

 lating to Occidents being especially interesting. The accident 

 death-rate is given as 4-70 per 1000 persons employed^ 

 below ground, a figure which, though necessarily varying 

 a good deal from year to year, shows upon the whole ar 

 downward tendenc}-. A comparison with the similar figure 

 for the Transvaal goldfields is decidedly in favour, of the 

 Kolar field, although in the Transvaal the accident death- 

 rate per 100,000 tons of quartz treated is less than in- 

 Mysore, due to the greater efficiency of the Kaffir as com- 

 pared to the Indian miner. In the Mysore there are 

 about 4000 persons employed for each ton of quartz 

 crushed, as against about 1000 in the Transvaal. A good 

 deal of space in the report is devoted to a discussion of 

 the " air-blasts and quakes," or violent bumps of ground, 

 due apparently to the sudden relief of the strains in the 

 ground as mining proceeds. These bumps have caused a 

 good many serious accidents, and up to the present no 

 means of preventing them has yet been suggested. It is 

 to be hoped that a further study of this intricate question 

 may lead at any rate to a determination of the conditions 

 under which they are likely to occur, this being the first 

 step towards taking measures to minimise the dangers 

 resulting from them. 



O.v assuming his extraordinary professorship at the 

 National University at Utrecht, Dr. E. van Everdingen 

 delivered an interesting address, on October 17, upon 

 " The Third Dimension in Meteorology." The establish- 

 ment of a separate chair for meteorology was, he thought, 

 an admission that it was now considered worthy of taking 

 a place among the older sciences. If we inquired in what 

 direction it had developed in the last twenty years, the 

 answer undoubtedly was, in the third dimension : height. 

 After glancing at the history of meteorology from the 

 earliest times, he referred to the great importance of Buys 

 Ballot's work in investigating simultaneous weather con- 

 ditions and in formulating his law of the relation of wind 

 to air-pressure, which is still the corner-stone of practical 

 meteorology-, and had infused new life into the subject. 

 He discussed in considerable detail the various methods 

 employed, and the valuable results obtained in the investi- 

 gation of the upper air by (i) manned balloons ; (2) kites ; 

 (3) captive balloons ; (4) registering balloons (with instru- 



