97 ELEMKM'MiY TlSSl'ES. 



3. Thin-walled cells, with large nuclei, lining the cavities. 

 In some cases the cells are much disorganized. 



4. Crystals in the adjoining tissue. 



5. Fragments of fibro-vascular bundles scattered through the 

 preparation. (Fig. 15.) 



PREPARATION SECOND: Make a tangential section and compare 

 with the previous study. 



Illustration Second: GLANDS in the leaf of JKn<'<il,//>tus. 



PREPARATION FIRST: Transections of a mature leaf can be pre- 

 pared as directed for the previous study. 



OBSERVE: 1. Large glands located on both upper and lower 

 sides of the section. 



2. The cavity of the gland. 



3. The large thin-walled cells, partly disorganized, lining the 

 gland, and the smaller thicker-walled ones just outside. 



4. The mesophyll and palisade cells surrounding the gland. 



5. The flattened epidermal cells above. 



PREPARATION SECOND: Make transections of the young leaf of 

 Eucalyptus and trace the formation of the gland, which results 

 from the breaking down and absorption of the mother cells. Stras- 

 burger, p. 164, DeBary, p. 201, Vine's Text Book of Botany, p. 40, 

 Goodale, p. 98. 



The Resin Ducts of Pinus were examined in the study of the 

 Tracheids of Coniferae. 



Water Pores. 



Illustration: LEAF TOOTH from Fuchsia. 

 PREPARATION: Several sections should be made serially, and 

 must include those through the apex of the leaf tooth, (p. 35.) 

 In the section passing through the center of the tooth : 

 OBSERVE: 1. The club-like enlargement at the outer edge. 



2. The epidermis, consisting of small cells, interrupted at the 

 apex and forming a circular opening the pore. 



3. Two or three layers of chlorophyll bearing cells beneath 

 the epidermis. 



4. The large region of the center of the section occupied by 

 the spiral marked tr<idi< nh. 



5. The water cavity between the pore and the long pure 



