SPERMATOPHYTES 311 



Examine cross, radial and tangential sections of pine', wood. Note 

 the annual rings, medullary rays, resin ducts, variation in size of cells, 

 thickness of cell walls, cell markings, etc. 



Examine a male cone. Note the arrangement of the sporophylls and 

 the position of the sporangia. 



Examine some of the microspores (pollen) under the microscopa 



Examine a female cone. Note the arrangement of the sporophylls 

 and the position of the sporangia. 



Examine prepared sections showing the gametophyte and the archegonia. 



Examine prepared sections showing the formation of the embryo. 



Examine mature cones showing the position of the mature seeds. Note 

 the form of the seeds. 



