148 ANATOMY OF STEM, ROOT AND LEAF 



powder.' Allow the mixture to stand after stirring, and pour off the clear 

 liquid into a well-stoppered glass bottle: keep in the dark. 



Collect a few thin leaves of plants and kill them by immersing them for a 

 minute in boiling water. Then place them in some *Eau de Javelle'; 

 leave them in it a few hours and when quite bleachedj wash in water for 

 an hour or two and then mount in weak glycerine. Examine with a low 

 power, observe the ramifications and endings of the bundles, also the paren- 

 chymatous bundle-sheath. Focus on the surface and note the form, number, 

 and size of the stomata and hairs. 



Fig. 76. — Diagrammatic longi- 

 tudinal section through the apex of a 

 stem, rf Dermatogen which gives rise 

 to the epidermis e ; c cortex produced, 

 from periblem a ; j vascular cylinder 

 produced from plerome b \ I leaves. 



Fig. 77.— Enlarged view of the apex of 

 the stem in the previous figure, d Derma- 

 togen ; a periblem ; b plerome ; v vessels 

 of the protoxylem ; /rudimentary leaves. 



THE GROWING-POINTS OF STEMS AND ROOTS. 



The growing-points or regions where the formation of new 

 organs and tissues takes place are situated at the end of the 

 stems and roots. 



(i) Growing-point oj the stetn. — The apex ot the stem is 



