416 



HUTCHINSON'S POPULAR BOTANY 





hear the contented hum of the bees amongst the young Laurel leaves 



[of Cerasus lusitanica] ; for 

 with no ulterior ends of 

 their own the prosaic green 

 bushes regale their friends 

 with the sweets secreted by 

 the yellow glands at the 

 bases of their leaves, and, 

 whatever may be said to the 

 contrary, afford a triumphant 

 proof that plants are not 

 exclusively selfish and utili- 

 tarian, as we in our half- 

 knowledge are sometimes 

 apt to imagine." Certain 

 species of Prunus (e.g. the 

 Cherry, P. cerasus) produce 

 nectaries in the form of 

 small red glandular swellings 

 on their leaf-stalks (fig. 489), 

 though the receptacular 

 tubes of the flowers also 

 secrete honey. The Broad 

 Bean, again (Vicia faba), has 

 nectaries on its stipules (fig. 

 490) ; so have the Vetch 

 ( V. saliva} and the Scabrous 

 Balsam (Impatiens tricornis). 

 These secretory glands 

 appear to be an ingenious 

 device for enlisting the 

 services of ants. 



It is probable that the 

 writer in Nature just quoted 

 would have modified his 

 statement had he inquired 

 a little further. The truth 

 is that the provision of 

 these nectar-glands on the 

 foliage of plants, so far from 

 being evidence of the plants' 

 philanthropy, is like much 

 that passes for the same virtue in our species dictated by strict business 

 -considerations. Instead of causing a net drain upon the capital, it yields 



.Photo by] [E. Step. 



FIG. 519. HAZEL FLOWERS (Corylus avellana). 



The long, swinging catkins consist of male flowers only. Th e female flowers 



are bud-like, with crimson threads (stigmas) protruding from the top. 



These later develop into the familiar Hazel-nuts. 



