great dissimilarity in the laftt% idu^f&^Bpe^diike; <$§fMei& 

 ture; 3. Configuration of surface ^t*K^ t riwHH^rfcpWDniriia 

 shelter and exposure); 4. The mechanical and chemical pro- 

 perties of the tu*ito@ '^olUiJf5iiolIhQr>liibcfoapiKl iaiediqBeijKBjft 

 properties of the subjacent rocksy&V^y^tt^ onomank t 9'iijgluv 



II. The combined influence of these, with some minor con- 

 ditions, determines the flora and vegetation of countries. 



III. As to comparative influence, these conditions are not 

 always in equal ratio or proportion ; but, when the more potent 

 condition or affinity is in its full play, the feebler one is less 

 apparent; and vice versa. Thus, when the temperature is best 

 suited to any given species, soil is of little moment ; but when 

 the temperature barely suffices, then soil may determine even 

 the existence of the speeies^inioiv eJi bns tesiol. boowniBriO 



IV. Comparing these conditions with each other, the in- 

 fluence of temperature (being less local) is chiefly shown in 

 the flora of a country ; while the other conditions (often par- 

 tial in their sway) may not at all affect the flora of a consider- 

 able tract, arid yet greatly modify its vegetation ; the latter 

 term having reference to the comparative prevalence, the 

 former to the mere existence, of the species. 



V. Comparing one species with another, some are more 

 influenced by one, some by another of the above conditions. 

 Some, for example, have a wide range of temperature, others 

 are indifferent to soil or moisture. dirw team niB-on aw <9gbhd 



VI. With regard to subjacent rocks, their influence is so 



frequently veiled by the other conditions, that for the most j 

 the flora of a country is not obviously affected thereby, though 

 the vegetation ( if? Smttft lfecWtaa^nivktobit^ibet»ayqiib ni ij& 



These appear to be geneWdOFulIa©; s^^taUrn^cfirteiiflbniM 

 the affinities between species and subjacent rocks, we may 

 add: — 1. That most species '^g$dv(\ew*H-<a>h£ v^mHds.laJraJ 

 widely different rc^k^ti^iighl^m^t^(e3pa1o?igdut)etmialbo£ 

 them ; 2. -TOa^^ry f&wQSpnicikstyif ^y^rkr©ab6«taeljdi{nited 

 fiy^nfe s%ffi3k*efefP§cfe^T3. That sevtai«f[$fofcs>haT* aniaffini^ 

 with a certa1H f r$fi^g§3d , Pfletfs^^ifl^ $ddtewisedo,*HMd igprDwio§ 

 ftfettl^^^hwl. « r ii^n^,^gra11ft^^giii(^i3wid^a4hifiafe cgara^di 

 have a resemblance in the species growing on them ; a similar 

 agreement is ^Ns^Pfbtte'fto&wkefV t^taep(M^liTOBM)ittGaDd^rap[ 

 rocks v serpentine rocks agP£©fbfWft ^fe3nrapT9itadB .-^Jfkatrbogs 

 tend to pf ctfftHfeath^jft&Gtfc T^^aJWfce~a&*lr grh9foutaraarsly)febdsE 

 of limestone oWefftflfc?" 'loiialni sdj gniworfa to wsiv b dlivr 



The evidence from which my concluskJ8#«dreA'awatfOTMi!d 

 be far too voluminous for insertion; but should any corre- 

 spondent be inclined to call in question their justness, I must 

 endeavour to defend that-or those so objected to. H.C W, 



