December 29, 1923] 



NA TURE 



951 



Research Items. 



The Cave of Macpelah. — In the concluding issue 

 for the year of Ancient Egypt, Sir FHnders Petrie 

 discusses the probable position of the double cave 

 below the Herodian monument which is described 

 in the lately published " Hebron, le Haram el Khalil," 

 by Pere Vincent and Captain Mackay. Owing to the 

 fanaticism of the present Arab population, the 

 authors of this work were not allowed access to the 

 subterranean parts. Our knowledge of these is 

 derived from an account, written in a.d. 1136, of an 

 examination of them in a.d. 1119 by the monks. 

 Sir Flinders Petrie 's conclusion is that the double 

 cave probably lies to the S.E. rather than to the 

 N.E. of the basilica-like chamber to which the monks 

 penetrated. A point of interest in connexion with 

 the superstructure is that while the internal pro- 

 portions indicate the Jewish foot as the unit, those 

 of the exterior conform to the Roman foot, the design 

 being based on the fact that the two units can be 

 worked together on a ratio of 10 : 11 in the length or 

 11-5 : 12-5 in the breadth. 



Rock Paintings in Papua. — Dr. W. Mersh Strong 

 has published in the December number of Man 

 photographs and tracings of a number of rock paint- 

 ings from the Central District of Papua. They were 

 found on a prominent whitish rock, and were executed 

 in a single monochrome red, apparently a preparation 

 of iron oxide. The designs included a cassowary, a 

 figure of a man, a scroll pattern, a double chevron 

 with pendent lines, possibly a tortoise, a man's face, 

 a crescent, and a hand. There is nothing to indicate 

 their age except that they are covered with a slight 

 fdm, probably of calcium carbonate derived from the 

 trickling of water. The present natives have no 

 knowledge as to who did them. Dr. Strong is of 

 the opinion that the face design suggests the face 

 moti^ of the Papuan Gulf, but points out that this 

 culture has its centre some two or three hundred 

 miles west of Port Moresby and scarcely comes 

 within a hundred miles of that area. He also refers 

 to the paintings of canoes and men in red monochrome 

 seen by Seligm^m in tlie Marshall-Bennet Islands. 



The Copi'i \io. — Two further instalments 



of tlif Rc'Tiort oi tin- (nniulian Arctic Expedition 

 1013 I'li'"^ li;i\i' iu--L l)rcii issued; these are "The 

 Pli\'si< ;il ( li;ir,i( Leristics of the Copper Eskimo," 

 1)\ 1). pnii'^s :ind " The Osteology of the Western 

 and (( lit til I liino," by John Cameron, being parts 

 B au'l < "t oliiuie xii. The measurements given 

 by Mr. |.nni .^ wore, for the most part, taken at 

 Coroiiaiinn (.nil. where the expedition spent two 

 years. -Mr. J(iims^ concludes that there is strong 

 support for lioas's view that Indian admixture in 

 Alaska has incrcasc(l the stature and produced a 

 niarki'il tendency towards bi-a(li\cc])lial\ ; airl ;liat 

 wliilc the Copper l^skmio show mot-.' rr-,i nilil.nii <■ 

 to thi iCastern Eskimo than to tlu' .\li-^l<an, ihiw 

 duitr Irom most other Eskimo in tlial tlic h'/.td is 

 sligh' -r and broader, although the rri)liah( 



indc ilK till' same as among the pnre-l)loo(h'il 



tril )■ ■. ai"i L I i ' ' a in'_; to not (■ I hat 



Mr no cN I'ii-i >;i()r t I >r. Md.i 11-, 



Ihr 

 M<'.| 



II 1)( Jil II \ ill, .M .■!,!!:..■ .11, M ! I I llIM -. , X\- <V. . . i|.l i t i|(• 

 p TO ] )<> f 1 I O U O 1 lair hrcailt ii to hc.nl brcidt h i - ilin -< tx . 



;ind till' lillic "•" '"■ ■ '" ol the cvc IS ptllhuluglCcd 



in I iriL'iii a II' I h( r<'. 



'a \. !■; ! i ' , \-. t h 



leg parasite, including the four " species " originally 

 described as the cause of the disease, H. M. Jennison 

 concludes, in a paper published in the Annals of the 

 Missouri Botanical Garden, vol. x. No. i, February 

 1923, that the blackleg disease of Irish potatoes in 

 North America and Europe is caused b\- a Schizomy- 

 cete which should bear the name Bacillus atroscpticus 

 van Hall. The following names are to be considered 

 only as synonyms : Bacillus phytophthorus Appel, 

 B. solanisaprus Harrison, B. melanogenes Pethy bridge 

 and Murphy. The pathogen infects the stems and 

 the tubers of the potato. Virulence of the parasite, 

 as tested by artificial inoculation, appears to be 

 dependent upon a rather delicate balance of tempera- 

 ture and water relations, and upon the sugar content 

 of the tissues inoculated. 



Cytology of Mutation. — Prof. R. R. Gates has 

 an important paper in the Annals of Botany, vol. 

 xxxvii. No. 148, October 1923, under the title " The 

 Trisomic Mutations of CEnothera," in which he 

 describes the occurrence in the Fj generation of the 

 cross Oenothera rubricalyx x CE. Hewettii of a mutant 

 with fifteen chromosomes, and discusses in connexion 

 therewith the whole question of the chromosome 

 mechanism associated with such types of mutant. 

 In CEnothera, relatively few mutants are found with 

 fourteen chromosomes ; these may be accounted for 

 in terms either of crossing over or of double " non- 

 disjunction." " Non-disjunction " has been called m 

 to explain the existence of the relatively frequent tri- 

 somic mutations (with 15 or 16 chromosomes). It is 

 assumed that on segregation two chromosomes of a 

 pair, instead of separating to different gametes, 

 both go into one cell ; thus in a pollen tetrad two 

 pollen grains will be fovmd with eight chromosomes 

 each instead of seven. When, as in the mutation 

 now described by Prof. Gates, two precisely similar 

 mutants appear in a small culture, it would seem 

 probable that both such pollen grains ha\e func- 

 tioned, so that the male parent is n-^fion^'.ble for 

 the extra pair of chromosomes. Ine\it.tlil\ in dis- 

 cussing such a problem the tim'slion an>e:> <is to w hat 

 extent the seven pairs of ehroinosomes in CEnothera 

 may be regarded as individuall\- distiiut. Prof. Gates 

 discusses the question in a tcntati\ e manner, direeting 

 attention to recent statements b\ llamr i oisi .mtl 

 Van Overeem (1922), who conclutie that thi -1 ^.wen 

 pairs are distinct and form a graded s( m - I 'rot. 

 Gates is evidently of opinion that tin-, (onrlu.Mou 

 is not yet sufficiently soundly based upon obser\ation 

 and experiment, but that the cytological coniplcxitics 

 of the probkiii well di snrve further exploration. 



I >isri.;i];r 1 1" >\ ,n- !! Shoals. — The report of 



the l)o\i' .Mariiir 1 .a 1 t'ullercoats, for lOJJ .13 



ri ml ain.s an intcre'^i in;.; [).. jn; b\' Mr ! '. '■ ''Mthe 



di t ribnt 1011 ol heirniL; :dioal>. \-.\ n 111 



l,i\ onr ol till- \ irw thai t lie lailure ol tne im In-i r\- m 



\',:\ w.i^din-, in ji.iit, lo .1 migration of you n- .North 



Si ' , 11 ri cdin'.; winter, f.ate m io.:o 



t h' , i o 1 w 1 1 >(■(•! ions, one ol w hu h 



III n I -I i ■ ■ 1 :i. M I .. .% .• 1 d'-. tow aids t h" 1 ^' 1 "rv - and 



Shetland, and tim other sniithssa: northern 



LM'i Ml]) t lirn-i ''. M , ..ij into an a : : : 1 i ilr ti> 



i^ri )w t h, an 1 a jiidlw The • • . ! n ni 



;;rew' mmh ib 1 f i h i -. ' ■, ' tiiil; 



indiist r\- in ail\ I i deimnd upon 



w Ihl !m r i he hii : rants Irom a 



d ia})id or ui slow :ni.wi!i, i.iiinr than iijion 



: 'nee of a pnrt n nl ir ■ imi ! i 1: m ,1 11 1 hor is 



the \ lew ;i may in 



.ii-jiriid n, -1 .Mlantic 



NO, 2826, VOL. I I2J 



