GROUPS OF TISSUES, OB TISSUE-STSTBMS. 51 



the Castor-oil Plant and Red Clover. The latter is very convenient 

 for study, as the uppermost joints will furnish as young bundles as 

 are required, while lower down all older stages may be obtained. In 

 these note the cambium-zone. 



(g) Make very thin cross-sections of a root of germinating Indian 

 corn. The first section should be made within a few millimetres of 

 the root-tip. Others should then be made at a greater distance. By 

 staining the specimens with carmine the sieve-regions may be demon- 

 strated better. Note the bundle-sheath. 



(Ji) Study in like manner the bundle in the stem of the Club-mosses 

 (some of the species are known as Gi'ound-pines), and if possible make 

 comparison with sections of the smaller Club-mosses (grown in green- 

 houses often under the name of Lycopodium, although they are in 

 reality species of Selaginella). 



(j) Dig up the underground stem of the common Brake-fern 

 (Pteris); preserve what is not wanted immediately in alcohol. The 

 bundles may be seen by the naked eye by making a clean cross-cut 

 and examining carefully in the region immediately surrounding the 

 two dark masses of fibrous tissue. Make thin cross-sections and study 

 with the microscope , comparing with Fig. 31. Longitudinal sections 

 in two planes should be made as in c and d above. 



(J) Make very thin longitudinal sections of some of the reduced 

 bundles which constitute veins and veinlets of leaves, e.g., in gera- 

 nium and primrose. 



(A;) Make similar sections of the bundles of petals, e.g., fuchsia. 



(J) Soak petals of fuchsia for seveial days in potassic hydrate, then 

 wash in water and carefully mount in pure water. The reduced 

 bundles may generally be well seen by this treatment. 



• 94. The Fundamental System of Tissues. — This system 

 includes all the tissues which in any part of a plant fre- 

 quently make up the bulk of that part, but are not included 

 in the epidermal or fibro-vascular systems. Thus if from 

 any stem, for example, we should strip off the epidermis 

 and then pull out the fibro-vascular bundles, that which 

 remained would be the Fundamental System of Tissues. In 

 those plants (of the lower orders) which have no fibro- 

 vascular bundles everything inside of the epidermis belongs 

 tg the fundamental system. On the other hand, in the 



