Mere variations of form arising from hybridisation or other causes hardly fall within the limits of this work, though it is quite impossible to say where variations end and malformations begin. There are, however, two or three cases cited by Mr. Darwin[371] from Gallesio and Risso to which it is desirable to allude. Gallesio 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. Risso describes a variety of the common orange which 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." =Sports or bud variations.=--These curious departures from the normal form can only be mentioned incidentally in this place, as they pertain more to variation than to malformation. The occasional production of shoots bearing leaves, flowers, or fruits of a different character from those found on the normal plant, is a fact of which gardeners have largely availed themselves in the cultivation of new varieties. The productions in question have been attributed to various causes, such as cross-breeding, grafting, budding, dissociation of hybrid characters, or reversion to some ancestral form, all of which explanations may be true in certain cases, but none of them supply the clue to the reason why one particular branch should be so affected, and the rest not; or why the same plant, at the same time, as often happens in Pelargoniums, should produce two, three, or more "sports" of a different character. These bud variations may be perpetuated by grafts or by cuttings, sometimes even by seed. With reference to cuttings a curious circumstance has been observed, viz., that if taken from the lower part of the stem, near the root, the peculiarity is not transmitted, but the young plant reverts to the characters of the typical form (Carriere). This circumstance, however, is not of universal occurrence. For further particulars on this interesting subject the reader is referred to Darwin's 'Variation of Animals and Plants,' i, p. 373, where numerous references are given, and wherein certain well-known and highly remarkable instances, such as the _Cytisus Adami_, the trifacial orange, &c., are discussed. FOOTNOTES: [366] 'Nature-printed Ferns,' 8vo edition, vol. ii, p. 197. [367] 'Gard. Chron.,' 1845. p. 790. [368] 'A New Arrangement of Phaenog. Plants,' p. 36. [369] 'Bull. Soc. Bot. France,' 1856, t. iii, p. 569.