146 PRACTICAL BOTANY 



2. Multicellular hairs, of conical form, and divided by septa, are 

 found in the Scarlet Geranium : cut transverse sections of the 

 petiole or stem, and observe these hairs together with capitate 

 hairs. Hairs of a similar type, but more bulky form, have already 

 been seen in Helianihus (p. 62). Some of the hairs of the Scarlet 

 Geranium may be seen to be branched, and this is often constantly 

 the case in other plants : as an example of a very simple branch- 

 ing, cut longitudinal sections of the leaf or stem of the Wallflower, 

 and note the unicellular, spindle-shaped hairs : more profusely 

 branched hairs are found on the surface of the stem or leaf of 

 species of Verbascum : it will be found better to take one of the 

 less woolly species, e.g. V~ nigrum. 



Preparations showing tufted hairs, in which numerous uni- 

 cellular filaments are inserted on a multicellular foot, may be 

 obtained from the leaf of species of Correa, or from the calyx of 

 Lavatera and other Malvaceae. Shaggy hairs, consisting of several 

 longitudinal rows of cells cohering laterally, are to be prepared 

 from the leaf of Hieracium pilosella. 



Scales have been alreadynoted in Hippuris (p. 110), and may 

 also be prepared from the leaf of species of Elceagnus, &c. 



In order to see glandular capitate hairs, transverse sections may 

 be made of the petiole of Primula sinensis : mount in water, and 

 observe the conical, multicellular stalk of the hair, and the round 

 terminal head, surmounted by a highly refractive, yellowish patch. 

 This highly refractive body consists ' of a resinous substance 

 secreted below the cuticle, and the resin may be dissolved by 

 alcohol or ether. Compare glandular hairs from the Labiatse, &c. 



A similar glandular secretion is found in connection with scales 

 in Humulus, where it appears on the upper surface of the scale, 

 and in Rhododendron ferrugineum, &c., where it occurs between 

 the cells of the scale. Compare also the massive glandular 

 colleters on the inner surface of the bud-scales of the Horse- 

 Chestnut : these secrete in large quantities a clear and sticky 

 balsam. For a description of other forms of hairs, both secretive 

 and non-secretive, and for a more detailed account of the place 

 and mode of secretion of resins and essential oils, reference must 

 be made to more extended text-books. 



The origin and development of emergences may be very well 



