Chap. X. CUCUEBITACEOUS PLANTS. 381 



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 Kolreuter. 138 



The forms of C. p&po 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 value 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 flat 

 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, faiinaceous, 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 millimetres 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 repre- 

 sented 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 

 ihe varieties with dwarfed stems, the leaves closely resemble each 

 > ther in shape. 



Those naturalists who believe in the immutability of species 

 often maintain that, even in the most variable forms, the 

 characters which they consider of specific value are unchange- 

 able. To give an example from a conscientious writer, 139 

 who, relying on the labours of M. Naudin, and referring to 

 the species of Cuourbita, says, "au milieu de toutes les varia- 

 tions du fruit, les tiges, les feuilles, les calices, les corolles, les 

 etamines restent invaiiables dans chacune d'elles." Yet M. 

 Naudin, in describing Cucurbita pepo (p. 30), says, "Ici, 

 d'ailleurs, ce ne sont pas seulement les fruits qui varient, c'est 

 aussi le feuillage et tout le port de la plante. Neanmoins, je 

 crois qu'on la distinguera toujours facilement des cleux autres 

 especes, si Ton veut ne pas perdre de vue les caracteres 



138 Gartner, ' Bastarderzeugung,' Xicotiana, see Kolreuter, 'Zweite 



1849, s. 87, and s. 169 with respect Forts.,' 1764, s. 53 ; though this is a 



to Maize; on Verbascum, ibid., ss. 92 somewhat different case, 

 and 181; also his ' Kenntniss der Be- 130 ' De l'Espece,' par M. Godron, 



tru^htung," s. 137. With respect to torn. ii. p. 64. 



