94 



THE TROPICAL AGRICULTURIST. 



[August i, 1882. 



HYBRIDS AND CROSSES: DEVELOPMENT 

 AND RECUPERATIVE POWERS OF 

 CINCHONAS. 

 Mr. Gammie, without, so far as we are aware, hav- 

 iii" seen Mr. Baildon's recent book, holds that what 

 is called Assam hybrid tea is not a hybrid at all, but 

 simply a cross between two varieties : the indigenous 

 tea of the Assam jungles and the cultivated tea of 

 China. He considers the parent plants as but differ- 

 ing forms of the same species, and we feel strongly 

 inclined to believe that he is right. Yet the large- 

 leaved tree, C. succiruhra, is scarcely more different 

 from the generally small-leaved and shrubby C. officin- 

 alis, than is the lurge-leaved one-stemmed tree-like 

 Assam tea from the small-leaved China, with its 

 numerous stems and low bushy habit. What is called 

 the Assam hybrid (an undoubted cross between the 

 tree-like Assam tei and the bushy China) is perfectly 

 and apparently permanently fertile, and, instead of 

 combining the bad qualities of both parents, as Mr. 

 BroHghton rashly asserted of Mr. Mclvor's cinchona 

 hybrids, it is really tupcrior to either and both ; 

 bein", in open cultivation, less delicate than the in- 

 digououe Assam, and more luxuriant in size and 

 quantity of leaf than the China. Now, if what is 

 known in Ceylon and Southern India as the " hybrid 

 cinchona" is really as fertile, and the seedlings as 

 true to type, as statements and descriptions indicate, 

 two (iuestious have to be settled : is the tree actually 

 a cross between C\ succinibra and one of the varieties 

 of C. officinalit, or is it merely a very large-leaved 

 variety" of C. officiiuili^, approaching C. succiruhra in 

 robustness of habit and size of foliage. If it is really 

 a permanent hybrid, then we have a right to con- 

 clude tliat C. succinihra and C. officinalis, differing as 

 they now do in habit and in foliage, are only 

 '"forms" or "races" of the same plant, identical iu 

 origin, but diversified in robustness, foliage, &c., by 

 differences of position as regards soil, climate, &c., 

 continued through a considerable period of time. II, 

 on the other hand, G. robusta, with its smooth, uu- 

 licheued, tall stem, rivalling or excelling O. succiruhra 

 as a tree and approacliiug it in size of leaves, is but 

 a very marked variety of 0. officinalis, then the two 

 so-called species, C. succiruhra and C officinalis, must 

 be regarded as closely allied forms, of a family in 

 which C. calisaya also holds a place, including O. 

 Led'ieriana, which, from the wonderful richness of its 

 bark has been erected intoanew and separate "species." 

 Botanically, no doubt, the flowers and fruits will 

 still be regarded as the scientific tests of species, 

 varieties &o., but bark characteristics, by which idone 

 the Australian settlers recognize the various "gums" 

 or Eucalypti, are still more marked in the case of 

 the cinchonas. \>\'V purposes of culture the test of 

 hark analysis, indeed, stand pre-euiinent. The question 

 of hybridization entirely aside, thecincuonas and, especi- 

 ally, the most valuable of all, C. Ledgeriana, are 

 so addicted to sporting, that the analysis of the bark 

 of a parent tree, whence seeds, cuttings or grafts are 

 to be taken, is all-important. It is very curious that 

 Col. Beddome should have adduced the dimorphic 

 chai'acter of the blossoms of cinchona as an objection 



to the iden of liybridization, seeing that Dr. Bidie 

 had adduced that very characteristic as the reason 

 why hybridization was inevitable, when the different 

 species, if species they really are, came to be cultiv- 

 ated side by side, or in such cluse contiguity, that 

 the pollen could easily be carried from tree to tree 

 by the agency of butterflies and biies. Dr. Trimen, 

 writing several years after Hooker and Thomson had 

 penned the passage in the Flora Indica as to hybridism 

 being rare iu nature, has stated that the process is not 

 unfrequeut in certain groups of plants in their wild state, 

 and the dimorphioblossoms of the cinchonas render them 

 not only liable to the crossing process in tlteir native 

 forests, but give them a special tendency to inter- 

 mixture when transferred to plantations and cultivated 

 iu large expanses. From this very tendency, a Cfylou 

 planter, Mr. W. Forbes Laurie, who has «losely 

 studied the whole question, theoretically and pract- 

 ically, hopes for the best possible results, in the 

 production and permanency of hybrids, specially 

 suited for luxuriant and profitable growth iu va- 

 rious zones of altitude and other climatal con- 

 ditions. Already, it seems proved that C. Bohusla, 

 most probably a hybrid, or cross (?) between C. sxwcirtdira 

 and C officinalis,* will flourish whei-e pure C. officinalis 

 refuses to grow or dies out, and even where C. succiruhra 

 does not succeed or attains but a poor success. While 

 awaiting the results of Mr. Moeus' hybridizing experi- 

 ments in Java, we trust our leading cinchona planters 

 in Ceylon will not be idle, but will try experiments 

 in crossing species and varieties, as well as in grafiing. 

 On the other hand, the tendency to hybridization 

 being established— and he must be a bold man who now 

 ventures to doubt this tendency in the cinchonas, — the 

 necessity becomes obvious of precautions to protect the 

 blossoms of superior Ledgers and other species or varie- 

 ties of ascertained vahie from being tainted by intermix- 

 ture of the pollen of inferior kiuds. So difficult 

 did Mr. Moens fiud this task in Java, that he got 

 -Government to consent to the eradication of the in- 

 ferior kinds, while he took to propagating the better, 

 by means of grafts placed on vigorous stocks of U. 

 succiriibra. Owners of plantations in Ceylon cannot 

 t>dce all the precautions which are possible to the 

 Director of the Java Government Plantations ; but 

 much can bu done by meaus of mush r bags, suuh as 

 even our anti-hybridity friend, Mr. W. Smith, placed on 

 his grand Ledgeriana trees, out of deferenee no doubt, 

 to the mistaken ideas aud prejudices of weak- need 

 brethren, who are unable to resist the strong and 

 cumulative evidence in favour of the tendency to 

 hybridism or crossing amongst the cultivated cin- 

 chonas. The tendency admitted, the clear duty of 

 cinchona planters is to avail themselves of it for the 

 production of beneficial r.-sults, and to take all pos- 

 sible precautions against the process, where they know 

 that it could only lead to deterioration of an exist- 

 ing superior type, such as C. led(jcriana undoubt- 

 edly is. Books on gardening afford full instructions 

 regarding the artificial production of hybrid planst. 

 The main principle is that the operator mu st cat 



* A crofs, on the assiunptiou that C. SKCciridira and 

 C. ojficiiwli/, however ditfereut iu habit, are merely varie- 

 ties' of- one species, like the Assam and China teas. 



