1878. | Glandular Hairs of Plants. 279 
From the end of the gland, when touched may be drawn out a 
gossamer thread of some length. The pulling out of the thread 
exhausts the gland in ue or in part, and causes it to collapse 
| or change its shape. Fig. 36 
shows a gland from which such 
a thread has been drawn. 
a å 
The fruit of Tecoma radicans, 
FIG. 34. trumpet creeper, has on its sur- 
Hairs of Petu- face numerous sessile cup- 
Fic. 38. 
Tip of gland 
of Martynia. 
FIG. 39. 
Fic, 36. Fic. Tip of gland of 
Fics. 35, 36, 37.—Glands of Martynia. Martynia. 
Fic, 35. 
shaped glands of which Fig. 40 shows a vertical section. In 
damp weather, or when not exposed to very dry air, these cups 
Fic. 40.—Gland of Tecoma radicans. Fic. 41.—Spot Fic. 42.—Stoma 
nba ta of same. on fruit of same. 
are heaped full with a drop of glistening liquid in each. Besides 
these, on the surface are numerous spots, like Fig. 41, in which 
numerous cells are clustered into a circular form. From these 
we may find all gradations down to a two-celled stomate, as in 
Fig. 42. 
On each margin of the petiole of Viburnum opulus and Passi- 
Jora are some cup-like glands which exude a sticky substance. 
Similar glands are found on the petioles of the cherry and some 
3 peaches. 
