2ib 



NATURE 



[Decemb! 



4- 



)\ I 



of these deserts, and set in motion business operations ) and Prof. I.loyd estimates that existing supplies wi:: 



•luolviii^ luillidiis of (;i|)ii.il li.is. <1 ui)(>ii llic anunint i l)e cxh:ui>t< d in a few years' time. Seed can be um- 



dt i.iw iii.iicii.il in ■^i;^llt. In ii)<i-' < liiiiiic;»l and '' minated .md plants easily raised by giving; a -ui .11 

 nil 1 hiiiii il rMi.Kiiuii pi. in; t up, and j^iiayuh- ' amount <>f ^li;id. and suhKurfarc irrifjation. On p. \z\ 



iiiM"!. iln.ii-li .111 inltrii'i lonlaininj^ a hijili j the .niilnir nin.itU-- ili.it 'tin- nujst fundan;enlal 



|nniii!.ii;( i>! iisiiiiiiis sui'^i.uu.. ^.M>n hfc.iiUf .'i v<tv , (•(•((n<iuii< ijui--ii<in tor ulii(h an an^u'-r will Iw south' 

 iiupoii.ini ill 111 in till- iinpoii-, ot llu- I nii< d si.ii,.,. ; in th<s<- I'.iU'"" '- '''•'' rrlalin^ tf> the jiroduction < 

 .\i ill.- jii. -. Ill (i.i\ till- <iuil.i\ of Aiii'i i( .111 (.ipii:il ill ruhlxT iiiid«r irrigation." In searching for a reply on. 



Ml \i( o iloiir is s.iid lo .inioiini io ,o,ochi, i (Inll.iis. li.is to tic ((intint with the statement that "The le<-s 



\ i.;oo(l (I, ;il h.is ;ili.;idv li.cn \wiiiin dc .ilini; witli , tilt- u.ilir tli<- tiruk-r thf hark fcortex) and viVo-ffrsa." 



Irrigated pl.mls naturally ^.^rou more vigorously bi. 

 produce wood al the cxfxnsi- of ( (<rtical tissu<>.. and 

 is largely the latter from which tin rntiht t i- 



;;ii,i\uli-. hill till' lllonoj^r.iph li\ I'lof. !■'. i'".. |.Io\(l 

 i^ .1 iiiosi \M'l((iiiii' .iddilioii lo spcrial nihhi i liiirn- 

 ;iiii. Its iMiihnis .iir thr outi-oiiii-, I'idI. I -loyd 

 si.iiis in iiis pii Inir. of ;in iii\ est it4;il ion i.iiiiid out 

 li\ oiluis .111(1 hinisill at \\\v iiis| ii^aiioii ol (■•■ri;iin 

 Mixic.in riilihn ciiiiip.inirs towards tlic elucidation of 

 till- i|u<stion ol thr |iroril.ii)li- cultivation of LTuayule 

 in till- disi-ii uiili .1 view io future mainli-nance of 



supplies. 



In addition to ijn- |)h\ sioloi^^y ol tin- plant uiid<r 



The book is evidenci- of a vast amount 

 undertaken in the spirit of enthusiasm, but its ulili; 

 for the M tieral read<r is curtailed by the want < 



condens.ition in dealini^ with experiments and tabular 

 results, and the ahsenre of defiriiie statements or deduc- 

 tive coiu'lusioiis. It is ( l.ihor.iteh- illustrated I'- 

 photo-litlio [dates, containing .i l.ir;;e number of phot' - 



KiG. a. — Guayule in a very dense growth. 



varied conditions, the main subjects dealt with are 

 questions of climate and soil, seed s^erniination, 

 methods of reproduction, results of croppinii, t nviron- 

 ment of the plant, its rate of growth, nuihods of 

 extraction, the possibility of maintainiiii; the supply 

 bv irrigation, and the effects of this upon the yield 

 of rubber. In the course of the investigation attempts 

 are made to throw light upon many interesting 

 problems in connection with the physiology of desert 

 vegetation. 



Much attention has been given to the formation of 

 resin and rubber, and the close connection between 

 the two. There appears to be no tube-like laticifennis 

 system as in other rubber-yielding plants, the rubber 

 being formed apparently in the cells of the resin-canals, 

 whilst the resin itself is found onlv in the canals and 

 not in the cells. 



The gua\-ule shrub is a very slow grower, a fifteen- 

 year-old plant being no more than 15 inches in height, 

 NO. 2198, VOL. 88] 



graphs and line-drawings of the minute histological 

 structure of the different parts of the plant, as Well 

 as by some fine photographs of desert surroundings. 



TEE AERONAUTICAL BLUE-BOOK FOR 



1910-11.^ 

 T^HE specific questions which form the subject of 

 ■*■ the experiments and observations described in 

 this report may be briefly described as follows : — 



The d< vi.-ition of air resistances from the law ot 

 proportion.ility 10 the square of the velocity and the 

 eflects of friction in tliis connection discussed theo- 

 retically by Lord Rayleigh and experimentally by 

 Messrs. Bairstow, Booth, Dr. Stanton, and .Mr. 

 Pannell. 



1 Technical Reports of the ' mmittee for Aeronaut'cs for the 



Year 1910-11 (with Appendiv 4. (Published by hii; Majesty's 



Stationerj- Office. London: Vi>>,ia:i ara Sons: Edinburgh: Oliver and 

 Boyd ; Dublin : E. Ponsonby, Ltd., 1911). Price 6x. 



