BIOLOGICAL STUDIES OF FIGS. 939 



no receptive female flowers, but which we now know are 

 characterized by their small number of female flowers, by 

 their large number of mule flowers, and by the total ab- 

 sence of gall flowers. To Gasparrini the large class of 

 Smyrna figs, which possess only fully developed female 

 flowers, was entirely unknown. At his time as well as 

 in our day this class of figs do not grow in Italy, and he 

 had no idea of their existence anywhere else. A theory, 

 therefore, which does not take in consideration all classes 

 of edible figs cannot be considered as absolutely plausible 

 and convincing. We now know through my own exper- 

 iments in pollination, and through the production of hy- 

 brid figs from Smyrna fig seeds by Mr. Maslin and myself, 

 that the pollen of the caprifig really is capable of pro- 

 ducing fertile seed when applied on the stigma of the 

 female flowers of the Smyrna fig. This does not, it is 

 true, prove with absolute certainty that the caprifig and 

 the edible fig are of the same botanical species, but it 

 does disprove Gasparrini's conclusion that the pollen of 

 the caprifig is incapable of fertilizing the female flowers 

 of the edible fig, when these flowers are properly devel- 

 oped. The presence of fertile seeds in many figs was 

 explained by Gasparrini through what is known botan- 

 ically as parthenogenesis or unsexual development (30). 

 That parthenogenesis is a possibility cannot be denied, as 

 it is proven to exist in at least one tropical fig, and proba- 

 bly exists in several, but it is a rare occurrence. And even 

 if taken in consideration it must be reinembered that it is 

 now proven that in the species in which it does exist it is 

 caused by the sting of a Blastophaga wasp, which stimu- 

 lates a growth in the nucellus, which might be called in- 

 ternal or seed budding (98). The existence of parthen- 

 ogenesis or self-budding without the impulse of outside 

 influences has not been shown to exist in the' edible fig, and 



