NA TUBE 



[July ii, 1907 



gullet, this whale does not require to open its mouth verv 

 wide; as the gullet is only from i| inches to 2 inches in 

 diameter, it indicates that the food consists of small 

 morsels. The sharp, enamelled tooth at the summit of the 

 tusk is probably used for tearing and rending soft-bodied 

 animals such as cuttle-fishes, and possibly for tearing 

 aside seaweeds when in search of food. 



The tusks are 14 inches in length, 2^ inches wide at 

 the jaw, i| inches at the summit beneath the conical real 

 tooth, and from § inch to ^ inch thick. On the back the 

 blubber was 3 inches thick, and ij inches on the bellv. 

 The oil was of fine quality, and had great penetrating 

 power, almost like paraffin. Owing to the advanced state 

 of decomposition of the viscera, the contents of the 

 stomach were not examined. 



From the foregoing it is evident either that previous 

 drawings and data in regard to Layard's whale are more 

 or less inaccurate, or that the present specimen indicates 

 a new species. The drawings show that the upper lip or 

 tip of the beak covers the lower lip, while the photographs 

 mdicate that the upper jaw slightly projects bevond the 

 lower, the reverse being apparently the case in Sclater's 

 and Moseley's illustrations. The lips were not hornv but 

 rather like hardish flesh. The skull is very asymmetrical, 

 the bulk of the frontal bones inclining from the right to 

 the left side. 



The creature had apparently been injured at some 

 previous time, as the tongue-bones and two vertebrje 

 showed signs of having been fractured and repaired. One 

 of the most remarkable features of this whale is the 

 small size of the flippers as compared with that of the 

 body. The backward position of the dorsal fin is also 

 noticeable. With the exception of those of the skull, the 

 bones are remarkably light and porous. Those of the 

 beak are, however, brittle, dense, and hard. 



F. \V. FiTzSi.MONS. 



Port Elizabeth Museum, May 30. 



The Radio-activity of Lead and other Metals. 



In the course of some experiments that have been 

 recently carried out in the physical laborator\- at Toronto 

 on the natural conductivity of air confined in 'vessels made 

 of different metals, a wide variation was observed in the 

 results obtained with different samples of lead. The lowest 

 conductivity observed with air enclosed bv this metal 

 corresponded to an average production of 23 ions per c.c. 

 per second, and the highest to a production of 160 ions 

 per c.c. per second. The lowest value hitherto recorded 

 for lead appears to be that quoted by Eve in his paper 

 in the Phil. Mag. of September, iqo6[ in which he gives 

 96 ions per c.c. per second as the number he obtained 'xvith 

 this metal. The sample of lead which exhibited the low- 

 activity just referred to was a sheet which had been used 

 as a lining in a case in the laboratory for nearly thirty 

 years. 



With zinc and aluminium receivers it was found that 

 on the average 15 ions per c.c. were generated per second 

 m the air which they enclosed. 



From measurenients made with the gamma ravs from 

 radium on the ionisation produced in air confined in a 

 lead cylinder (0 when unlined. and (2) when lined with 

 thm sheet aluminium, due allowance being made for 

 absorption, it was found that the ionisation in a lead 

 cylinder due to the gamma rays was one-half that obtained 

 with the excited secondary radiation. On the other hand, 

 with an aluminium cylinder, the ionisation due to the 

 secondary radiation was found to be approximately one- 

 half that produced by the gamma rays. .Assuming these 

 results to hold for the penetrating 'radiation from the 

 earth, it follows that on the average 9 ions per c.r. per 

 second are generated in free air by this radiation. It also 

 follows that the difference between the natural ionisation 

 in air obsserved with the aluminium cylinder, viz. 15 ions 

 per c.c. per second, and that found with the least nrtive 

 lead, viz. 23 ions per c.c. per second, can be wholly ex- 

 plamed by differences in the secondary radiation e-xcited in 

 the two metals. This result, combined with the obser\-ed 

 differences in the conductivity of air enclosed in vessels 

 rnade of different samples of lead, goes to show that the 

 high activity usually obser\'ed with lead is due to the 

 NO. 1967, VOL. 76] 



presence of active impurities in it, and not to the exist- 

 ence of any intrinsic activity possessed by the metal. In 

 this connection it is interesting to note that Elster and 

 Geitel (Phys. Zeit., November, 1906, and May, 1907) have 

 recently been able to extract from commercial lead oxide 

 and a sample of lead an active substance which they 

 suggest may possibly turn out to be radium F. 



In the experiments described above, the measurements 

 were made with a sensitive quadrant electrometer on air 

 confined in cylindrical vessels 60 cm. high and 24 cm. in 

 diameter. J. C. McLesn.^n. 



L'niversity of Toronto, June 2;;. 



Inheritance and Sex in Abraxas grossulariala. 



In February, 1906, in conjunction with the Rev. G. H. 

 Raynor, I gave a paper to the Zoological Society on the 

 inheritance of a variety of the moth .Iftra.vai grossulariala 

 and its relation to sex (Proc. Zool. Soc., 1906, vol. i., 

 p. 129). We found that when the var. lacticolor (ftavo- 

 fasciata) was crossed with the type it behaved as a 

 Mendelian recessive, disappearing entirely in generation F,. 

 When two heterozygotes were mated together, var. 

 lacticolor reappeared, but only in the female sex, roughly 

 half the females and all the males being typical. When 

 a heterozygous male was mated with /<ii(ii:olor female, the 

 variety appeared in both sexes in the offspring, viz. in 

 about half the males and half the females. When, how- 

 ever, a lacticolor male so produced was paired with a 

 heterozygous female, we found that all the males were 

 typical and all the females lacticolor. This result was 

 given in our paper with some hesitation, since it was 

 founded on a rather small number of specimens (29 c?> 

 II 9), but this year it is amply confirmed. I have reared 

 116 males and 74 females from six families of this mating, 

 and every male is typical, every female lacticolor. Mr, 

 Raynor has also reared equally large numbers with the 

 same result. From a family of the converse cross, on the 

 other hand {lacticolor Q x heterozygous r^), I have reared 

 24 type Q , 22 lacticolor (J, 17 type 9. 18 lacticolor O, a 

 fair approach to the expected equality in each sex. 



I think it may be concluded definitely that in this case 



(i) The type is completely dominant. 



(2) DR; xDR-- gives 'DDo-l-DR ^•. DRO+RR9. 



(3) RJxDR ' aives DRc'-hRo. DRO-i-RO. 



(4) DROxRc gives DRcJ. R?. 

 •(5) ROxR:' gives Re?, R9. 



(In [2] above the absence of DD females has not ben- 

 proved.) 



This confirmation of our previous results seems to me • 

 lend some support to the provisional hypothesis of sex 

 determination outlined in the paper referred to. 



L. DOXC.ASTER. 



University of Birmingham, July 2. 



THE DOVBLE-DRIFT THEORY OF STAR 

 MOTIONS. 

 'X'HE problem of determining- the motion of th<.> 

 *■ sun amongst the stars has undergone a great 

 change in consequence of Prof. J. C. Kapteyn's in- 

 vestigations, which have recently become known. 

 These researches indicated that the stars surrounding 

 us do not form a simple system, but a dual one. 

 From a discussion of the motions of the stars of 

 Bradley's catalogue. Prof. Kapteyn demonstrated the 

 existence of two great streams of stars passing j 

 through one another, and found the directions of 

 motion of these streams relative to tlie sun and to one , 

 another. The Bradley stars, numbering about 2600, 

 are mainly stars visible to the naked eye ; they cover 

 nearly three-quarters of the celestial sphere, and 

 throughout the whole of this area Prof. Kapteyn 

 found the same two streams prevailing, and it seemed 

 probable that all the stars he examined belonged to 

 one or other of the two streams. 



The investigations with which this article morp 

 particularly deals are based on the proper motion- 



I 



