flowers of such sorts as Hubbard Seedless and the Sultanina (the 

 Thompson Seedless, a raisin grape widely cultivated on the Pacific 

 Coast) indicate that these also have flowers of this general type. In 

 respect to maleness the sex of these plants is highly developed, but 

 their seedlessness shows that femaleness is weak and but partially 

 developed. In the case of plants that produce seedless and seeded 

 fruits in the same cluster there is indication that femaleness is 

 irregular in its development and may appear in various grades among 

 flowers of a single cluster altho such a mixing may not be apparent 

 in the general appearance of the flowers, and not especially con- 

 spicuous in the general appearance of the clusters of fruit. (See 

 Plate IV.) 



Noll (1902) has called fruits which are produced without polli- 

 nation parthenocarpic. The available evidence indicates that this is 

 a relatively rare phenomenon. Such types should probably be 

 classed quite differently than those in which pollination is required 

 for any setting of fruit. They may perhaps be regarded as more 

 strongly female or at least as strongly fruitful. There may be some 

 question as to whether parthenocarpy is a phenomenon of vegetative 

 or of reproductive vigor. However, the numerous grades of seed- 

 lessness which are found show, it seems to me, that when pollination 

 is required seedlessness is to be regarded as a stage in the series of 

 intersexes. 



PLANTS WITH TWO OR MORE FLOWER TYPES INTERMIXED 



In some plants it is plainly evident from an examination of the 

 flowers that such extreme types as the purely staminate and what 

 resembles the perfect hermaphrodite are intermingled in the same 

 cluster. The latter may,, however, give no fruit, seedless fruits, 

 seeded fruits, or various mixtures of these. Figures 8 with 9 and 

 11 with 12, show this condition. 



The plant bearing the flowers shown in Figs. 8 and 9 produced 

 no fruit in 1920 which suggests that the pistils that are formed are 

 functionless. The erect stamens are of good size and the anthers 

 dehisce normally but only about 5 per cent of the pollen germinated. 

 The grains that did not germinate were with few exceptions shriveled 

 and aborted (Fig. 10). 



The plant bearing the flowers shown in Figs. 11 and 12 produced 

 a " light " crop in 1920, the clusters were decidedly " loose," the 



