94 



CELLULAR TISSUE. 



since hitherto the observers, with the exception of Hanstein, have treated the objects as 

 exceptional, and have not thoroughly considered the points of structure in question. As 

 examples of glandular hair-structures, which may here be described rather more in detail 

 than above, we may begin with the bladder-like hairs, and cite once more those of 

 Cistus creticus. The flat leaf of this shrub is grey with numerous branched hairs, and, 

 especially at the base, with long pointed unicellular erect appressed hairs. It bears also 



short, multicellular hairs, which are capitate and 

 glandular above ; and lastly, numerous spindle-shaped 

 large glandular hairs, which consist of a lower broader 

 part composed of many disc-shaped cells, and a thin 

 cylindrical, 1-4 celled terminal part (Fig, 36). The 

 glandular structure occurs on the slightly widened 

 apex, and often in places on the lateral wall of the 

 terminal part. 



Besides the examples of capitate glandular hairs and 

 villi, and the scales connected with them already men- 

 tioned, may be named those figured by Weiss from the 

 calyx of Maurandia semperflorens (/. c, Fig. 279) and 

 Antirrhinum majus (I.e., Fig. 310), and by Hanstein 

 from the leaf-buds of Ribes (/. c, Fig. 30-33), Syringa 

 (Fig. 68, 69), Helianthus annuus (Fig. 91, 92). The 

 adjoining figure (Fig. 37) represents a glandular 

 villus from the petiole of Conoclinium atropur- 



FlG. 36. — Spindle-shaped glandular hairs of 

 Cistus creticus (375). a before tlie secretion be- 

 gins. <-, (i with secretor>' bladder on the apex ; in * 

 the secretion extends from the apex far back- 

 wards ; c" the apex of c after removal of the secre- 

 tion by alcohol and ether. 



Fig. 37. — Conoclinium atro- 

 purpureuin (142). From a longi- 

 tudinal section tlirough the epi- 

 dermis of a young petiole, e — e 

 epidermis, with a glandular 

 villus ; c terminal cell of a villus ; 

 ^ terminal cuticular bladder, 

 filled with resin. 



pureum, with a non-capitate terminal portion consisting of two rows of disc-shaped cells, 

 on which the equally high, hemispherical secretory mass, surrounded with cuticle, is 

 seated. All the Labiatae (comp. Meyen, Ungcr, Hanstein, Rauter, Martinet / c.) have 

 besides various other forms of hairs, short glandular hairs, consisting of a pedicel-cell 

 lying in the epidermis, a short stalk-cell borne by this, and seated on the latter a 

 glandular head, covered by a great secretory bladder. The head is in the simplest 

 cases a spherical cell; e.g. Pogostemon Patschouli, Fig. 38: in most cases a spherical 

 group of four cells (Lamium album, Rauter, /, c. ; Plectranthus fruticosus. Fig. 21, -^, p. 

 59) ; also, it not uncoinmonly grows on, with further division, to a multicellular peltate 

 scale, as in the case of the large, about 12-celled, depressed glands of many species 



