SUPPLEMENT 



can be easily shaken dry and have not increased in weight. But it 

 seems to be established that viscid and glandular hairs sometimes 

 attract water to a marked degree. The same viscid substance which 

 in dry air acts like a coat of varnish and prevents evaporation, in 

 moist air may actually attract the water. Kerner states that the 

 glandular hairs of common geraniums absorb water, and believes 

 that, with the water, they take in nitrogenous compounds and even 

 dissolved mineral salts. In the geraniums the water enters the termi- 

 nal cells of the hairs, the thickened layer of the cuticle here being 

 discarded ; in the Eremocarpus the water enters the cells at the basis 

 of the hairs and partially drives out the air from the stellate branches. 



The castor oil plant, which is such a flourishing shrub in Southern 

 California, also absorbs water through its foliage, not through hairs 

 but probably through the little warts and cups that have sometimes a 

 very sticky surface. The little warts are under the teeth of the leaves 

 at their very tips ; the cups are at the basis of the leaves where ribs 

 converge, and along stems, always on the upper surface. L,et the 

 children see for themselves that dew, fog or rain collects at exactly 

 these places. Let them also immerse the blade, not the cut petiole, 

 of a wilted leaf in water and see that it revives. 



Plant No. 2, Fig. 15, Trichostema lanceolatum, is sometimes called 

 blue-curls because of its long exserted stamens, or camphor weed, on 

 account of the odor, or flea-weed, because of its disagreeable foliage. 

 This plant, too, seems to me to absorb moisture through its glandular 

 hairs. The hairs are pictured at the end of the chapter. The flowers 

 of the Trichostema have a unique method of reserving their honey 

 for bees. The slender tube of the corolla is bent back on itself at such 

 a sharp angle that only a very minute creature could turn the corner. 

 But a large bee, one with >a tongue long enough to reach the honey, 

 clinging to the lower petals is heavy enough to straighten the tube 

 and at the same time the essential organs of the flower, anthers and 

 stigmas, are brought with force against the tip of the bee's body. 

 In the younger flowers the stigmas are not mature, but the open 

 anthers leave a goodly supply of pollen on the bee's back. When he 

 visits an older flower, as in the picture, the stigmas strike this pollen 

 and the flower is cross-pollinated. The hive bees are so fond of the 

 honey that they will often be found searching among the fallen 

 corollas in the dust for any honey that may remain in the tube, for 

 hive bees seem to be unable to exhaust the honey from the flowers on 

 the plant. 



The other plant in Fig. 15 is Zauschneria Californica, var. micro- 

 phylla, Gray. As it belongs to the fuchsia family, Onagracese, its 



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