486 



NATURE 



[February 8. 19 12 



disr;iM- uliicl, "ui .imiMin-i ili'- liiiM'"'- 



polaini on lli' --..iilvui u. I'lif ln-,s «,| hi-- 



;mi()nj4sl 111!' In|.|.'.i»ii.inii Ii.hI. I.. • n -i > l;|',iI i1i;iI lli. 

 f,;.,r,,p,...,i)s li.id I. II 11 i.lili.Md iii . in|)ln\ imii uilli 



, |Hl-.ll I'll! illlli ill' I III 1 'III ill' 1 ■!! ' ■l'^' 



iiiu.ilU liciiii; sir.uid'i! 111! ill'- sIhu. 

 i,\,i, ill, -,liinll tK'lii whirl) \v;is ;i|)|).illiiu; iinii 



.nlliiw-. .1 ilivct i|iiiiin III ill'- S.inkuiu ;iih1 iln iilumI- 

 1,11-, |iii.>is (.11 it-, li;inl<s, iK r'«i, rii(k\ « iilK i i>in^i in 

 1,1.1, ,s til .1 liri^lil (it .'iiii ti 1 I, in ill'' (i.Miiiii--. iif wliich 

 n.siid innuimi.iM'' i^ha ii;nriii-. lli-' in\ >lcriuus 

 vi,i<.i i.liiiid I" 1>\ ill' ;iuilini .1-, ,1 111 i-dwclliiij,' 

 niHluiii.il l»r.i-^l ullirin.C .1 wild ri\ w.i^ pi (>l);il)lv a 

 II I ' -In I .i\. 



111,. |;.i-,iinLli-, lllr r>,ili!il:i l.iiici lll'ir l'i\i- nl p.iilli- 

 in- picluiis and u-m- ui •-i^nallint4 i^iui^^si. ilu- 

 Hakoiit^d III Ciiilial Africa (nol lu In- c. ml usi-il with 

 111'' i|iiil'' di-^tiiirl I'.aUdn.^d "I wisiiin Con^joland I. 

 till- caniiilial Hankulu. tin- r>aiu.i dw.iiK, tho lintoiid'-. 

 Haliuiula, Haliilia, Havoii -i uii'iii «, .ind, aliovr all, tin- 

 ;n-i-l(icralic Ini^-lmni^' 1, an- nm-i iiiti-ir-l ini^K d'- 



FiG. 2.— An Akela cutting up his food. From " Land and Peoples of the 

 Kasai." 



scribed. The Batwa dwarfs seem to have varied from 

 four feet eight to five feet in height (a photograph is 

 given of them). The journey through the Bankutu 

 cannibals was not devoid of risk; the traveUers owed 

 their safety probably to the curiosity excited by their 

 presence without an escort, yet well sujiplicd witli 

 means. On p. 147 an accurate and vrry tttcctivt 

 description is given of the " airlessness," disheartmini; 

 mist, and excessive damp, of the dense forest. " In 

 the daytime the atmosphere of the wocidN resembles 

 that of a hothouse; at night that of ;; a '.' 



The zoological discoveries of the expedition due to 

 the author of this book, consisted mainly 01 .t new 

 species of very small duyker antelojio (Ccpliah^plttis 

 simpsoui), and an interesting traiisitidnal ty|H' ot 

 buffalo, a subspecies also named after Mr. Simpson, 

 which differs from the dwarf hulTalo of the Congo in 

 being black-haired (chocolate in the females) and not 

 reddish-brown, and in having horns set much wider 

 apart than those of Bos caffer nanus. The bosses of 



NO. 2206, VOL. 88] 



pNdii s j(no!oj;r.'i]>ns <.i iiu- ii< , 

 ('tmniAund will be of much int' 



•! rthnfilo^'i'^tii. .\lthough n: 

 M,it nian\ ol ih' ni would 



■////• /• / y / < / ol- (.!•.■ \ss ()\ ih'ilT TRI. 



AM()\<i ill' iiiuu inttri-ling i<-ults obtairv 

 i!i. \\ Mliurii luNiJcrinRiital I'Vuit Farm pe; 

 III. -; p ni.irkable is the discovery that grc' 



-n-~ . I d. I. tcrious ffTfct on fruit trees. 



w.i^. i.;i -I oli-i-rv.itions, and was < 



uiih ,ii III till- third report in I903. 



•a luiinlii I- ol i\|i<-riinciit> iKivt' since been made, 

 ai' di -.(lih'd in tin- ihirteenth report recently issi 



I hi- -liii id r< >uli <if 1,'r.i— <iiig the ground after iii« 

 Mil - h.i\i !). I 11 pl.ini.-d is the arrestation of all hea!'h]f 



■ ilic alisolutr stunting of the tr 

 ;. ,.. - , 11 ii^iht in colour and unhealthy. 

 siiiiilarh In ronns iii^hi rolourtd, whilr the fruii 

 its gn-tii nialttr and hromn s waxy yellow dr bri^ 

 red. This ( jfi ri is particularly marked in the c;: 

 ajijili Ill's. It the i^rassing is done gradually 

 trees .nidinniod.iie themselves somewhat to the •■ 

 ing loaditioiis, .md tln.aliy make ^^rowth and \ ■ id 

 fruit, though the\ iievir do - ■ • " - ■ ' — 

 is .d'si-nt. 



A numhiT of hy|iOtile>rs li,m i,..i, . .N.i.i.n.- 

 r.iUUt for this,. i)li,iiomena. The grass roots , 

 liu aeration of th- soil, the amount of carbonic 

 |)resent, the soil temperature, moisture, food su 

 &c.. and thev ni.i\ , .as thi Inited States Bure. 

 .Soils idainis, i\ri-. !.• pnisonous substances. Thee. 

 invesiiL^.itioiis showid that neither the aeratior 

 temiiiiMture et'fec-is jilayed any ji.art in tin- matt' 

 f.ar .It le.ist ,is tr- 1 -n^wih is eoneerned ; the pt • 

 directed to the investig 

 lal results proved tha 

 III-, s Were not due t< 

 li\- the i.ir.as~,. Th,. ati 

 the si;;ns of sUtTei " 

 during wei scasi 

 deii-rminations of tiie water content ot the gras- 

 lilled soil at interv.als tliroughout a year reveal< - 

 diffirences sutTicieiit to acc^iunt tor the efTet ' 

 more conclusive evidence w.as olitained by 

 trees in pots, some with, otli.rs without, K'-"" 

 keeping all equally moist ; tlie del. lerious < tti 

 the grass remained equally m.irked. 



It is more ditViculr to test the elTect of gra — 

 the food suiii)iv of the tree, because our knowk_„i 

 of what constitutes the food either of fruit trees 

 of grass is still far from complete. Pot experimen 

 with the ordinary nutrient suhsi.uices all led to n€ 

 tive results, and the conclusion is drawn that 

 elTc'ct {)n the ftxxi sujiply is not the determining facte 

 \or did it appear that the i^-rowth of grass cau9 

 anv sutVicienf [ihvsical alter.itioii in the soil to accou; 

 for the risidts. There remains only the hypothes 

 that plant roots fxcrete sonie suhst.mce toxic to ti 

 tree roots, and for this the autliors claim to have 

 fair amount of indirect and sonie direct evideiUl 

 When perforated trays of s.and containing growil 

 grass w 1 re jil.iced on the surface of the soil in whl 

 tile ir.i s \\,re ^LTrowinsj, so that ttie washings frO 

 the gr.iss re.ached the tree roots with practically i 

 exposure to the .air. tiny had a deleterious eSt 

 nearly, if not quite, as threat as wh^" ./'-■cc w; 



e\|>erimenis ,ir<- ■ 

 of the other f.ici. - 

 h.irmful etlects on ilu 

 •ahstraclion of moisture 

 trei's exhihitcd noii'- ot 

 drouuht or of r(co\rr\ 



1 Thirteenth Report of the Woburn Experimental V 

 Duke of Bedford, K.G., F.R.S..and Spencer U. Pickeri 



Byl 



