336 



FRUITS. 



Chap. X. 



artificial aid; thus he positively states that seeds taken from lemon- 

 trees (0. lemonum) growing mingled with the citron (C. medico), which 

 is generally considered as a distinct species, produced a graduated series 

 of varieties between these two forms. Again, an Adam's apple was pro- 

 duced from the seed of a sweet orange, which grew close to lemons and 

 citrons. But such facts hardly aid us in determining whether to rank 

 these forms as species or varieties ; for it is now known that undoubted 

 species of Verbascum, Cistus, Primula, Salix, &c, frequently cross in a 

 state of nature. If indeed it were proved that plants of the orange^ tribe 

 raised from these crosses were even partially sterile, it would be a strong 

 argument in favour of their rank as species. Gallesio asserts that this is 

 the case ; but he does not distinguish between sterility from hybridism 

 and from the effects of culture ; and he almost destroys the force of this 

 statement by another, 17 namely, that when he impregnated the flowers 

 of the common orange with the pollen taken from undoubted varieties of the 

 orange, monstrous fruits were produced, which included " little pulp, and 

 had no seeds, or imperfect seeds." 



In this tribe of plants we meet with instances of two highly remarkable 

 facts in vegetable physiology: Gallesio 18 impregnated an orange with 

 pollen from a lemon, and the fruit borne on the mother tree had a 

 raised stripe of peel like that of a lemon both in colour and taste, but 

 the pulp was like that of an orange and included only imperfect seeds. 

 The possibility of pollen from one variety or species directly affecting the 

 fruit produced by another variety or species, is a subject which I shall 

 fully discuss in the following chapter. 



The second remarkable fact is that two supposed hybrids w (for their 

 hybrid nature was not ascertained) between an orange and either a lemon 

 or citron produced, on the same tree, leaves, flowers, and fruit of both pure 

 parent-forms, as well as of a mixed or crossed nature. A bud taken from 

 any one of the branches and grafted on another tree produces either one ol 

 the pure kinds or a capricious tree reproducing the three kinds. Whether 

 the sweet lemon, which includes within the same fruit segments of differ- 

 ently flavoured pulp, 20 is an analogous case, I know not. But to this 

 subject I shall have to recur. 



I will conclude by giving from A. Bisso 21 a short account of a very 

 singular variety of the common orange. It is the " citrus aurantium fructu 

 variabili" which on the young shoots produces rounded-oval leaves spotted 

 with yellow, borne on petioles with heart-shaped wings ; when these leaves 

 fall off, they are succeeded by longer and narrower leaves, with undulated 

 margins, of a pale-green colour embroidered with yellow, borne on foot- 

 stalks without wings. The fruit whilst young is pear-shaped, yellow, 

 longitudinally striated, and sweet ; but as it ripens, it becomes spherical, of 

 a reddish-yellow, and bitter. 



Peach and Nectarine (Amygdalus Persica). The best authorities are 



zione,' p. 69. 



13 Gallesio, idem, p. 67 



19 Gallesio, idem, pp. 75, 76 



la Riprodu- 



20 'Gardener's Chronicle,' 1841, p. 





613. 





21 'Annales du Museum,' torn. xx. 



76. 



p. 188. 



$ h 



