246 



NATURE 



[April 21, 192 1 



parthenogenetic offspring failed to show any segrega- 

 tion towards either parent. It is concluded that in 

 such a clone segregation does not take place. The 

 results would be more complete if it were also shown 

 that in sexual reproduction of this hybrid segregation 

 did take place in F, or later generations. Such a 

 result would also be interesting as indicating whether 

 the difference between the parent species depends on 

 a single factor or on a larger number of genetic differ- 

 ences. Prof. Agar has shown that each species con- 

 tains a large number of clones, each of which will 

 perpetuate its differences in parthenogenetic repro- 

 duction. 



The 1920 report of the council of the British 

 Research Association for the Woollen and Worsted 

 Industries has just been issued. The chief feature in 

 the report is a fully illustrated description of the 

 research laboratories and workshops at present being 

 fitted up in Leeds. In addition to paying 5400!. for 

 the property upon which the central laboratories are 

 being installed, 2oooL has been advanced for the pur- 

 chase of a site for an experimental carding installa- 

 tion in Huddersfield. The director, Major H. J. W. 

 Bliss, is gradually building up staffs for the physics 

 dnd colloid chemistry, chemistry, engineering, and 

 biology departments, and, although fundamental 

 soundness is not being sacrificed to the too prevalent 

 desire for quick returns, useful researches have already 

 been taken in hand. Thus four publications (Nos. 7, 

 8, 9, and 10) on important problems have been issued 

 to subscribers, and there are indications of useful work 

 nearing completion on spinning, oils, scouring and 

 milling, and last, but not least, those fundamental 

 problems which no private firm can be expected to 

 undertake. The sheep-breeding experiments, from the 

 wool point of view, in which the association is col- 

 laborating with other bodies — notably the Agricultural 

 Departments of England and Scotland — are deemed so 

 important that a special pamphlet has been issued as 

 an appendix to the annual report. Many useful breeding 

 experiments are being made this season — largely under 

 the stimulating influence of Prof. Cossar Ewart, of 

 the University of Edinburgh — and it is hoped from 

 these comparatively small-scale experiments to obtain 

 useful data for others on a much larger scale. It is 

 evident also from this appendix that, in addition to 

 producing new crosses, the association is anxious to 

 improve the present breeds, and in conjunction with 

 the Royal Agricultural Society and other show com- 

 mittees it is about to engage in battle against " grey 

 hair," "kemps," and a deterioration in "wool 

 quality," following mistaken ideas on the relation- 

 ships of wool and physique. 



An interesting point is made in Water-Paper 418 

 of the U.S. Geological Survey, on " Mineral Springs 

 of Alaska," where it is remarked that permanent 

 ground-frost surviving in the region from the Glacial 

 epoch has an important influence in diminishing the 

 mineral content of surface-waters. In Seward Penin- 

 sula alluvium has been found frozen to depths of 

 more than 200 ft., while on hill slopes facing north- 

 ward ice occurs within 2 ft. of the surface. Erosion, 

 moreover, is prevented by the general covering of 

 NO. 2686, VOL. 107] 



moss, grass, and forest. K. H. Brooks, the author 

 of this section of the paper, indicates a more normal 

 composition for river-waters derived from the moun- 

 tainous regions, where streams flowing from the 

 snows cut deeply into rock. 



Thb noble genus Nelumbo is now represented by 

 two species only, the Indian lotus of Asia and 

 northern Australia and the American lotus or great 

 water-lily, found in eastern America from Ontario to- 

 7° S. lat. in Brazil. E. W. Bert-y (U.S. Geol. Surv., 

 Prof. Paper 108-E) describes a new species from the 

 Eocene of Meridian, Mississippi, resembling some of 

 the European fossil forms, and he gives a world- 

 map showing how the long history of the genus is 

 revealed by its Cretaceous, Cainozoic, and present 

 distribution. The author attributes the southward 

 migration of Nelumbo to the inclemency of the Glacial 

 epoch, and its entire disappearance from the Old' 

 World west of the Caspian to the natural obstacles 

 presented by European structure, which prevented it» 

 escape southward into Africa. 



The Meteorological Magazine for March contains 

 an article by Dr. J. S. Owens on London smoke-fogs. 

 The method adopted by the Atmospheric Pollution 

 Committee for measuring the impurities deposited 

 from the air by large open-topped gauges is acknow- 

 ledged as insufficient. It has now been supplemented 

 bv a method of ascertaining the quantity of suspended 

 matter in the air. An automatic instrument is made 

 to filter a fixed volume of air through a small disc 

 of white filter-paper at short intervals, and a measure 

 is made of the impurities left behind on the filter- 

 paper. Continuous records have been obtained from 

 three stations in different parts of London during 

 the past winter. The records for foggy days are kept 

 separate from days with ordinary weather, and the 

 records for ordinary week-days, excluding Saturdays 

 and Sundays, are kept separate from the results for 

 Saturdays and Sundays respectively. The air is purest 

 between midnight and early morning, and the amount 

 of impurity rapidly increases at about 6 or 7 a.m., 

 reaching its maximum at about 11 a.m. on week-days 

 and at noon on Sundays. A subsidiary maximum 

 is shown at about 5 p.m., after which the 

 impurities rapidly decrease. It is shown, with prob- 

 ably some approximation to truth, that the impurities 

 are due to domestic smoke rather than to industrial 

 furnaces. The author acknowledges that at present 

 the data are scanty, but expresses the hope that 

 further results will prove instructive. 



The discovery by Sir E. Rutherford two years ago 

 that o-particles from radium C on their passage 

 through nitrogen or oxygen produced a small number 

 of particles with range 1-3 times that of the original 

 particles made it possible that the swift particles from 

 thorium C discovered by Rutherford and Wood in 

 19 14 might have been produced by the passage of the 

 o-particles of range 8-6 cm. through the mica screen 

 used in the experiments. In the April issue of the 

 Philosophical Magazine Dr. Wood shows that this is 

 not the case, and Sir E. Rutherford describes how 

 he has obtained, by the aid of a powerful source of 

 thorium C presented to him by Dr. H. McCoy, of 

 Chicago, a sufficient number of the long-range par- 



