108 GYMNOSPERMS 



microspores develop into the male gametophyte which consists 

 of two prothallial cells, a generative cell and a tube cell. 

 Pollen grains are carried by the winds and fall directly upon 

 the ovule. 



Female Gametophyte. The megasporophylls are also 

 arranged in cones. Each ovule is open or not enclosed in a 

 chamber, and contains a megaspore which develops into the 

 female gametophyte, consisting of an embryo sac with 

 several archegonia. After fertilization the ovules develop 

 into seeds containing the young embryo, sporophyte with 

 several cotyledons or seed leaves making the seeds of this 

 group polycotyledenous. 



Sporophyte. The sporophyte is a tree with true roots, 

 stems, and leaves. 



Stems. The stem increases yearly in diameter because 

 of the presence of a formative region between the wood and 

 the bark. 



Leaves. The leaves are needle or scale-like, and are 

 usually angled or several-sided in outline. 



