30 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



embryonic cells and their suspensors are ready to penetrate 

 the endosperm; this latter has become greatly modified, 

 a cone-shaped mass of special tissue having been formed 

 immediately beneath the group of archegonia. The cells 

 of this tissue are specially organised for the production of 

 starch and its subsequent preparation as food for the 

 growing embryos, thus taking up the work hitherto 

 performed by the egg and jacket cells. 



The advancing suspensors pierce and corrode the cell 

 walls in much the same way as did the pollen tubes on 

 their passage through the nucellus. When the embryonic 

 cells have been carried a short distance into the endosperm 

 they commence growth, and should more than one egg be 

 fertilised, a keen competition must ensue for supremacy. 

 For instance, if four eggs have been fertilised — we have 

 already noted that this frequently happens — there will 

 probably be sixteen embryos struggling for a food supply 

 sufficient only for one of them. As it is possible for only 

 one of them to succeed in producing a normal seed, fifteen 

 of them have to give way. Some few make but little 

 headway, and soon become absorbed into the tissues of the 

 survivors; others continue the struggle until development 

 is fairly advanced, even a few surviving until late 

 September. Generally, however, by this time, one has in 

 some manner proved its superiority, and continues its 

 progress alone to full development and maturity : this is 

 reached at the end of October. The embryo, with its 

 cotyledons (about seven), now enveloped with endosperm 

 closely packed with starch for future food, passes to rest 

 until the warm days of spring. It is a complete seed 

 fitted with a wing whereby when liberated from the cone 

 it may be borne to a congenial spot, where, if all goes well 

 it will germinate, and finally become a tree like that from 

 which it was shed. 



To close without some reference to the chromosomes 



