90 



Experiments ivith Primula sinensis 



In the more common double (Text-fig. A), the supernumerary 

 segments are inserted at the throat of the tube, one segment occurring 

 opposite each petal. The anthers are somewhat exsert, and are attached 

 just at the base of the supernumerary segment ; the position of the 

 anthers might easily lead one to suppose that the flower was " thrum- 

 eyed," were it not for the long style and the size of the pollen. The 

 supernumerary segments are reversed ; that is to say, the external side 

 resembles the upper (internal) surface of the normal petal, while the 

 internal side is like the back of the latter'. 



A B 



In the old-fashioned double (Text-fig. B) the doubling is more 

 complete than in the more usual form, and a number of supernumerary 

 segments occupy the centre of the flower'-. The supernumerary segments 

 are of different orders; the primary segments are inserted, one opposite 

 each petal, on the corolla tube at the constriction which, in the normal 

 type, would mark the position of the stamens. These primary segments 

 are not reversed, but they bear secondary supernumerary segments 

 which show the reversal*. The latter are attached to the primary 

 segments at, or rather below, the region corresponding with the throat. 

 Our plants of this type are of a pale pink, so that the reversal of the 

 colouring is not so conspicuous as in the full coloured races of the 

 oidinary double, but it shows clearly in that the yellow "eye" at their 

 base is on the external side, while the internal side resembles the outside 

 of the primary segments and of the ordinary petal. The plants bear 

 no stamens at all and the female organs are generally represented by 



> Cf. Masters, Vegetable Teratology, 1809, p. 449. 

 - Cf. Masters, loc. cit. p. 315. 



■' lu both kinds of doubles the morphology of the reversed segments i.s obscure, and it 

 is not clear that these structures are of the same nature in the two case.s. 



