226 BUTANICAL GAZETTE 
[are 
in the embryo sac determining the form of the sexually pro- 
duced embryo, give the same form to the adventitious embryos. 
Tretjakow suggests that the development from the antipodals 
represents apogamy, the antipodals being homologous with the 
vegetative cells of the prothallus, but this explanation will not 
apply to the origin from nucellus cells. Jeffrey has nothing to 
‘Say on this point, while Hegelmaier concludes his paper thus: 
eren Formen mehr nur ein zufalliges sei. Aber mindestens fiir diese letsent 
ist doch wohl die Annahme unabweisbar, das irgendwelche gemeinschaftliches 
Ursachen vorhanden sein miissen, fiir deren Erkenntniss durch ein Spiel mt 
morphologischen Homologien nichts zu gewinnen sein wiirde. 
In general for a new feature one of three origins may be ; 
Supposed. First, it may be some incidental growth or functional 
condition. Here comes the explanation of budding, and Piet 
ing. But its very different morphological origins ee: : 
this. Here comes its explanation as apogamy, but this does ™ 
explain the origin from the nucellus. Third, it may be 
stages in the development of something new. It & 
yet be of any service to the plants, for many of the emory | 
absorbed before the seeds are ripe, and in other case one 
but one develops, though perhaps one of the smaller may" 
. by j, Its ong 
times take the place of the leader if this is destroy : 
in several distinct groups and by several distinct met" 
to imply that there is some virtue in the develop! aie 
extra embryos, and that their appearance Is nee 
uence, whatever it may be, which here forms ® 
than mere morphological inertia, and whiclt elsewhere 
