356 FEUITS : Chap. X. 



the pips of sweet oranges produced 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 re- 

 produced 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, 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 fruit, 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, 16 they largely 

 intercross without artificial aid; thus he positively states that 

 seeds taken from lemon-trees (C. lemonum) growing mingled with 

 the citron (C. medic/), which is generally considered as a distinct 

 species, produced a graduated series of varieties between these two 

 forms. Again, an Adam's apple was produced 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 ca^e ; 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 of species, is a subject which I shall fully discuss in the 

 following chapter. 



15 ' Teoria della Riproduzione,' p. 53. 



17 Gallesio, ; Teoria della Riproduzione,' p. 69. ,8 Ibid. p. 67. 



