Chap.X. ORANGE GROUP. 335 



varieties of the wild Citrus medica, but that the shaddock (Citrus decu- 

 mana), which is not known in a wild state, is a distinct species ; though its 

 distinctness is doubted by another writer "of great authority on such 

 matters," namely, Dr. Buchanan Hamilton. Alph. De Candolle, 13 on the 

 other hand— and there cannot be a more capable judge— advances what he 

 considers sufficient evidence of the orange (he doubts whether the bitter 

 and sweet kinds are specifically distinct), the lemon, and citron, having been 

 found wild, and consequently that they are distinct. He mentions two 

 other forms cultivated in Japan and Java, which he ranks as undoubted 

 species; he speaks rather more doubtfully about the shaddock, which 

 varies much, and has not been found wild ; and finally he considers some 

 forms, such as Adam's apple and the bergamotte, as probably hybrids. 



I have briefly abstracted these opinions for the sake of showing those 

 who have never attended to such subjects, how perplexed with doubt they 

 are. It would, therefore, be useless for my purpose to give a sketch of the 

 conspicuous differences between the several forms. Besides the ever- 

 recurrent difficulty of determining whether forms found wild are truly abo- 

 riginal or are escaped seedlings, many of the forms, which must be ranked 

 as varieties, transmit their characters almost perfectly by seed. Sweet 

 and bitter oranges differ in no important respect except in the flavour of 

 their fruit, but Gallesio 14 is most emphatic that both kinds can be propa- 

 gated by seed with absolute certainty. Consequently, in accordance with 

 his simple rule, he classes them as distinct species ; as he does sweet and 

 bitter almonds, the peach and nectarine, &c. He admits, however, that the 

 soft-shelled pine-tree produces not only soft-shelled but some hard-shelled 

 seedlings, so that a little greater force in the power of inheritance would, 

 according to this rule, raise the soft-shelled pine-tree into the dignity of an 

 aboriginally created species. The positive assertion made by Macfayden 15 

 that the pips of sweet oranges produce in Jamaica, according to the nature of 

 the soil in which they are sown, either sweet or bitter oranges, is probably 

 an error; for M. Alph. De Candolle informs me that since the publication of 

 his great work he has received accounts from Guiana, the Antilles, and 

 Mauritius, that in these countries sweet oranges faithfully transmit their 

 character. Gallesio found that the willow-leafed and the Little China 

 oranges reproduced their proper leaves and fruit; but the seedlings were 

 not quite equal in merit to their parents. The red-fleshed orange, on 

 the other hand, fails to reproduce itself. Gallesio also observed that the 

 seeds of several other singular varieties all reproduced trees having a 

 peculiar physiognomy, but partly resembling their parent-forms. I can 

 adduce another case : the myrtle-leaved orange is ranked by all authors as 

 a variety, but is very distinct in general aspect : in my father's greenhouse, 

 during many years, it rarely yielded any seed, but at last produced one; 

 and a tree thus raised was identical with the parent-form. 



Another and more serious difficulty in determining the rank of the 

 several forms is that, according to Gallesio, 1 * they largely intercross without 



I :S e ^ raP hf 0t i P - 863 ' ~^H^'s <Bot. Misc./ vol. i. p. 



leoria della Riproduzione,' pp. 302 ; vol. ii. p. 111. 



16 ' Teoria della Riproduzione,' p. 53. 



