SPERMAPHYTES. 



STEM. 



I. Gymnosperm, 



Make with a razor thin sections transverse, radial, 

 and tangential of pine wood that has been soaked 

 in water. Mount in dilute glycerine and study 

 with A A 2 and D 2. 

 Observe in the transverse section : 



1. The annual rings. 



Compare the two edges of a ring. 



2. The thick-walled pitted tracheids. 



3. The narrow medullary rays. 



Make a diagram with AA% showing the relation of 



the autumn to the spring ivood, and of the wood 



to the medullary rays. 

 With D 2 sketch accurately a small part of the 



section. 



In the tangential section observe : 



1. The tracheids : their form, their arrangement, 



and the pits in their walls. 



2. The medullary rays. 



Make a diagram showing the relation of tracheids 



and medullary rays. 

 Sketch accurately with DZ a small part of tht 



section. 



Observe in the radial section : 



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