46 BOTANY. 



Practical Studies. — (a) Strip off a bit of the epidermis of a Live- 

 for-ever leaf. Mount it in alcohol to avoid air-bubbles, and after- 

 wards add water and a little potassic hydrate. Epidermal cells and 

 breathing-pores may be well seen. 



(b) Prepare in like manner the epidermis of both upper and under 

 surfaces of a cabbage-leaf. Note the breathing-pores on both sur- 

 faces ; note also the bloom. 



(c) Make very thin cross-sections of a cabbage-leaf (by placing a 

 piece of leaf between two pieces of elder-pith) so as to secure cross- 

 sections of the epidermis. Note the thickened outer wall of the epi- 

 dermal cells. In some cases the separable cuticle may be seen. Now 

 and then a breathing-pore may be seen in cross-section. 



(d) Make similar sections of the leaf of the oleander, cactus, com- 

 pass-plant, holly, or any others of a hard texture. Note in some 

 cases (oleander and cactus) that there are several layers of epidermal 

 cells. 



{e) Mount in alcohol a few hairs of tickle-grass (Panicum capillare) 

 as examples of simple one-celled hairs. 



(/; Mount in like manner hairs of petunia, verbena, or walnut as 

 examples of hairs made of a row of cells. Note that many of these 

 are glandular. 



(g) Mount in like manner hairs of the mullein as examples of 

 greatly branched hairs. 



80. The Fibro-vascular or Skeletal System. — In most of 

 the higher plants portions of the interior tissues early be- 

 come greatly differentiated into firm elongated bundles, 

 which run through the other tissues and constitute the 

 skeleton of the plant. They are composed for the most 

 part of tracheary, sieve, and fibrous tissues, together with 

 a varying amount of parenchyma, and have a general simi- 

 larity of arrangement and aggregation. In a few oases 

 milk-tissue is associated with those above mentioned. To 

 these collections of tissues the name of Fibro-vascular 

 Bundles has been given. They are also called Woody 

 Bundles and Vascular Bundles, but the name first given is 

 to be preferred. 



81. In many plants the fibro-vascular bundles admit of 

 easy separation from the surrounding tissues; thus in the 



