CHAP, r.] AURANTIACE^. 311 



of the species, the petioles are winged ; that is, 

 they are dilated into little leaves on each side 

 (see dm Jig. 122). The different species vary 

 chiefly in the number of stamens, the thickness 

 of the rind, the shape of the fruit, and in the 

 wings of the petioles. In the Citron these wings 

 are wanting entirely, and instead of them there 

 are spines in the axils of the leaves ; there are 

 generally forty stamens, and the rind of the fruit 

 is very thick. In the sweet Lime, the petioles are 

 are slightly winged, and there are about thirty 

 stamens ; the fruit is small and round, with a 

 slight protuberance at one end like that of the 

 Lemon, and the pulp is sweet. In the Lemon 

 the petioles are somewhat winged, the flowers 

 have about thirty stamens ; the fruit is oblong, 

 with an acid pulp, and a thin rind. The Sweet 

 Orange has winged petioles, about twenty 

 stamens, and a fruit with a thin rind and sweet 

 pulp ; and the Seville Orange differs principally 

 in having a thicker rind and bitter pulp. The 

 China, St. Michael, and Malta Oranges, with 

 many others, are all varieties of the Sweet 

 Orange {Citrus Aurantiuni) ; and there are 

 many other species, which I have not thought 

 it necessary to describe. — All the species above- 

 mentioned are natives of Asia, and most of them 

 of China, but they have been so long cultivated 

 in Europe and America, as to have become 

 almost naturalised. 



