358 



CUCURBITACEOUS PLANTS. 



Chap. x. 



presque comparable a, celle des especes les mieux caracterisees." One 

 variety, l'Orangin (pp. 43, 63), lias such prepotency in transmitting its 

 character that when crossed with other varieties a vast majority of the 

 seedlings come true. Naudin, referring (p. 47) to C. pepo, says that its 

 races "ne different des especes veritables qu'en ce qu'elles peuvent 

 s'allier les unes aux autres par voie d'hybridite, sans que leur descendance 

 perde la faculte de se perpetuer." If we were to trust to external differ- 

 ences alone, and give up the test of sterility, a multitude of species would 

 have to be formed out of the varieties of these three species of Cucurbita. 

 Many naturalists at the present day lay far too little stress, in my opinion, 

 on the test of sterility ; yet it is not improbable that distinct species of 

 plants after a long course of cultivation and variation may have their 

 mutual sterility eliminated, as we have every reason to believe has occurred 

 with domesticated animals. Nor, in the case of plants under cultivation, 

 should we be justified in assuming that varieties never acquire a slight 

 degree of mutual sterility, as we shall more fully see in a future chapter 

 when certain facts are given on the high authority of Gartner and'Kol- 

 reuter. 138 



The forms of C. pepo are classed by Naudin under seven sections, each 

 including subordinate varieties. He considers this plant as probably the 

 most variable in the world. The fruit of one variety (pp. 33, 46) exceeds 

 in volume that of another by more than two thousand fold ! When the 

 fruit is of very large size, the number produced is few (p. 45) ; when of 

 small size, many are produced. No less astonishing (p. 33) is the variation 

 in the shape of the fruit ; the typical form apparently is egg-like, but this 

 becomes either drawn out into a cylinder, or shortened into a fiat disc. We 

 have also an almost infinite diversity in the colour and state of surface of 

 the fruit, in the hardness both of the shell and of the flesh, and in the 

 taste of the flesh, which is either extremely sweet, farinaceous, or slightly 

 bitter. The seeds also differ in a slight degree in shape, and wonderfully 

 in size (p. 34), namely, from six or seven to more than twenty-five milli- 

 metres in length. 



In the varieties which grow upright or do not run and climb, the 

 tendrils, though useless (p. 31), are either present or are represented by 

 various semi-monstrous organs, or are quite absent. The tendrils are even 

 absent in some running varieties in which the stems are much elongated. 

 It is a singular fact that (p. 31), in all the varieties with dwarfed stems, 

 the leaves closely resemble each other in shape. 



Those naturalists who believe in the immutability of species often main- 

 tain that, even in the most variable forms, the characters which they con- 

 sider of specific value are unchangeable. To give an example from a 

 conscientious writer, 139 who, relying on the labours of M. Naudin and 



138 Gartner, ' Bastarderzeugung,' 

 1849, s. 87, and s. 169 with respect to 

 Maize ; on Verbascum, idem, ss. 92 

 and 181 ; also his ' Kenntniss der Be- 

 fruchtung," s. 137. With respect to 



Nicotiana, see Kolreuter, ' Zweite Forts., 

 1764, s. 53 ; though this is a somewhat 

 different case. 



139 ' De l'Espece,' par M. Godron, 

 torn. ii. p. 64. 



