July i, 1882.] 



THE TROPICAL AGRICULTURIST. 



^S 



as the foundation of all progress. To a Dar- 

 wiuiau, therefore, the wonder should not be that 

 the offspring of hares and rabbits (leporides) should 

 bo fertile after their kind, but that a mulu the off- 

 spring if ass and horse should be generally sterile ; that 

 in many cases hybrids should be invariably sterile and 

 that in a very liirge number of cases separated specits, 

 even when crossed, refuse to produce offspring at all. 

 Darwin very candidly confesses utter ignorance oflhe 

 laws on which such varying results depend. Mr. Gam- 

 mie is right and we were and are right in saying that 

 hybridism is the rarest possible occurrence in nahve ; 

 but when man takes either animals or plants in hiind, 

 and subjects them to conditions the reverse of natuial, 

 there is really no saying what the consequences m.iy 

 be. We regret to say that we cannot join our good 

 friend in his sceptical queries as to the obtaining of 

 prolific offspring from a union of hares and rabbits. Dar- 

 win in 1S68 wrote that the statement of such results 

 having been obtained was doubtful, but it seems now 

 to be established beyond all possible doubt. The writer 

 of the article in the Encydopiviiia Brilannka writes : 

 —"The hare and rabbit are said occasionally to bre-'d 

 together, and Iheir offspring to be highly fertile when 

 crossfd with either parent species." But there is no 

 qualifying "It is said" in the article in Chiimbers — 

 the statement is express and definite: — "The most 

 remarkable example on record of generative power in 

 hybrids is afforded by the experiments of Mr. Eouse of 

 Angouleine, who finds that he can cross hares and 

 rabbits to any extent, and who has thus by breeding 

 /e^orirfes established a new aud lucrative enterprise in 

 agriculture. For a full account of these experiments, 

 which are well deserving of a Irial in this country, the 

 reader may consult Brown-Sequard's JournnI de laPhy- 

 siologie, vol. II. pp. 374 3S3. These experiments have inflic- 

 ted a severe blow on the popular doctrine of the perma- 

 neuco of species." There may Lie some question still as to 

 the variety of hare used in these experiments. The 

 common hare of Ceylon bears a good deal of resemljl. 

 auce to a rabbit. We suppose the rabbits were Hie 

 domc-ticated ones, some of the numerous and divergent 

 varieties, all descended from the small grey wild one ; 

 just as the pouters and tumblers and fantails and 

 carriers and runts of th^ pigeon family trace their 

 desoent from and are ever inelined to revert in shape 

 aud colour to the blue rock pigeon. We should not 

 now be much surprised to hear that pigeons and 

 bautaus had been successfully paired, for we already 

 know that the offspring of the common domestic fowl 

 and the phe;/saut is a fine robust bird. That sledge 

 dogs should pair with wolves is not wonderful, seeing that 

 such dogs are themselves only partially tamed wolves, 

 but it is startling to hear of a hybiid or cross between 

 a dog and a lioness. As for plants, they are appar- 

 ently capable of being hybridized by grafting and 

 budding as well as by the lutermixtuie of pollen 

 of ditferent species and varieties : in some eases, actu- 

 ally dift'erent genera. On the other band all man's 

 efforts sometimes fail. A plant will refuse to 

 be influenced or will be influenced injuriously by 

 pollen from a plant of a different species, while in 

 eome cases the pollen of a particular tree, used to 



fertilize the blo.ssom3 of that tree acts like poison. 

 To come to the cinchonas : they are, in their native 

 Andean habitat, scattered in groups amongst other 

 forest trees. Mr. Gammie seems to think that so 

 situated, in a natural state, hyoridism, from the in- 

 fluence of insects or otherwise, would not be likely to 

 occur. Investigation might well be directed to 

 this question, for whatever tendency to hybridism is 

 due to the existence of dimorphic blossoms %vould 

 render the cinchonas, to at least a certain extent, 

 liable to hybridization or crossing, in the case of 

 species and varieties. One wonderful German insisted 

 that all the cinchonas cultivated in India ard Java 

 were merely hybriils ! In that case, it would be dif- 

 ficult to know where to look for species. But whetlier 

 Darwinians or not, we are all agreed in recognizing 

 specific differences suiBeient between C. sziccirubra, C. 

 officinalis and C. calisaya to constitute them distinct 

 species, although, no doubt, all very closely allied, 

 in the constituents of their bark if not in the 

 botanical characteristics. Of the large-leaved robust 

 C. surcinihra there are only two varieties. Of the more 

 shrubby aud smaller leaved C. officinalis there are at 

 least half-a-dozen varieties, aud so with the beautiful 

 velvet-leaved C. calisciya. Crosses between varieties of 

 the same plant we may look for, and we may expect 

 such crosses to be fertile, and to be sometimes im- 

 provements on the original stock. Closely ]>lantcd as 

 our trees are too, somctiiues all species intermixed, 

 and insects abounding, we must also be prepared for 

 the .ippe.arance of hybrids between succirubra and 

 officinalis ; between succirubra and calisaya ; and be. 

 tween the dift'erent varieties of the species ofEcinalis and 

 the difl'erent varieties of the species calisaya. The 

 general belief is that C. robusta is a hybrid between 

 C. succirubra and C. officinalis. If so the question as 

 to its continued fertility is interesting aud important; 

 but here we must pause for today. 



A SUBSTITUTE FOB, PERUVIAN BARK. 



The following is an extract sent to us by our 

 Loudon correspondent : we 1 ave little or no belief in the 

 supercession of cinchona bark by artificial quinine and 

 will refer to the matter more fully again : — 



Ever since the year 1820, when Pelletier and Caven. 

 ton discovered that the fever-desiroying power of 

 Peruvian bark was due to an alkaline, crystaline 

 subbtance, which they named quinine, chemists have 

 been searching either for a sntistitute for this costly 

 medicament, or for a cheap method of making it 

 artificially. Endh'ss substitutes have been proposed 

 from the bitter principle of angoslura bark to spiders' 

 welis : but none of them have succeec'ed in ousting 

 quinine from its position as the first aud best 

 of febrifuges. From lime to time, too u-e have heard 

 rumours that some hitherto unknown cliemist had 

 discovered the method of making quinine from chiap 

 material'', but the rumours have died away without 

 echo. At last, however, we seem to be on the thres- 

 hold of something positive in this latter direction. M. 

 E. J. Mailmen^, a distinguished French chemist, has 

 definitely .announced verb;illy that he has succeeded in 

 making quinine artificially — that is to say, without 

 having recourse to the natural bark. He does not 

 wish to announce the de'ails of his process just yet, 

 as he does not consider them perfect ; but he has 

 deposited a sealed packet containing an account of 

 them with the secretary of the Frecch Academy of 



