40 BOTANY. 
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. 
(€) Mount in alcohol a few hairs of tickle-grass (Panicum capillare) 
as examples of simple one-celled hairs. 
(f) 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. 
78. The Fibro-vascular System—In most of the higher 
plants portions of the interior tissues early become greatly 
differentiated into firm elongated bundles, which run 
through the other tissues. They are composed for the 
most part of tracheary, sieve, and fibrous tissues, together 
with a varying amount of parenchyma, and have a general 
similarity of arrangement and aggregation. In a few cases 
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. 
79. In many plants the fibro-vascular bundles admit of 
easy Separation from the surrounding tissues; thus in the 
Plantain (Plantago major) they may readily be ‘pulled out 
upon breaking the leaf-stalk. In the leaves of plants, 
where they constitute the framework, they are, by macera- 
tion, readily separated from the other tissues as a delicate 
network. In the stems of Indian corn the bundles run 
through the internodes as separate threads of a considera- 
ble thickness. 
80. In the fibro-vascular bundle of the stem of Indian 
