3o8 



MORPHOLOGY. 



ize the embryo which pushes its way into the endosperm from which it 

 derives its food (tig. 362). 



626. Homology of the parts of the female cone.^ — Opinions are divided as 

 to the homology of the parts of the female cone of the pine. Some consider 

 the entire cone to be homologous with a flower of the angiosperms. The 



Fig. ,^0i. 

 Archegonium nf white riine at stage ijf fertilization, en, egg nucleus; spn. sperm 

 nucleus in ctmjugatiMn with it; n6, nutritive bodies in cytoplasm of large egg; 

 cpt, cavity of pollen tube; vn, vegetative nucleus or tube nucleus; sc . stalk cell; 

 spn, second sperm nucleus: pr, portion i>f prothallium or endusperm; 5^7. starch 

 grains in pr.llen tube. The sheath of jacket cells of the archegDuium is n^t shown. 

 (Alter Ferguson.) 



entire scale according to this view is a carpel, or sporophvll, which is divided 

 into the cover scale and the ovuliferous scale. This division of the sjiom- 

 y^h\ll is considered similar to (hat whii h we have in isoctes, where the spo- 

 rnphyll has a ligule above tlie sporangium, or as in ophioglossum, where the 

 leaf is divided into a fertile and a sterile j)ortion. 



Others ln-lieve that the ovuliferous siale is composed of two leaves situ- 

 ated ialerally and ( onsoHdaled representing a shont in the axis of the bract. 

 T'here is some suppoii \i->\' thi-. in Ihe f,u 1 that in (ciiain abinuanal cones 

 which show jirolifcTation a sliort axis ai^jicars in the axil c>f the l)rai.t and 



