9 8 



PART I. — ORGANOGRAPHY. 



of which produces a pollinium, which is club-shaped in form, and 

 has at its lower end a sticky disc, as represented in Fig. 294. 

 The delicately fringed lip is connected at its base with the long, 

 tubular nectary, b, Fig. 193, which contains the honey secretion. 

 The flowers are visited by butterflies, whose long tongues enable 

 them to probe the bottom of the tube. In this process the 

 visiting insect squeezes the thick basal portion of his tongue 

 between the sticky discs of the pollinia, which adhere firmly, and 

 are withdrawn from the anthers when he flies away. The pol- 

 linia, when first withdrawn, 

 stand out nearly at right 

 angles to the insect's tongue, 

 but after a few 

 moments, by a 

 drying process 

 which they un- 

 dergo, they bend 

 obliquely down- 

 ward and some- 

 what inward, so 

 that when the 



Fig. 293. Fig. 294. 



Fig. 293. — Flower of Habenaria ciliaris, with three rounded sepals, two strap-shaped 

 petals which are fringed at the apex, a fringed lip with the base of which is connected a long, 

 tubular nectary, b; a column, a, consisting of a stigma depressed between two anther-lobes, 

 each of which contains a pollinium. c is the ovary of the flower. The flower is magnified 

 about two diameters. 



Fig. 294, A and B. -A, Column of combined stigma and stamens, separated from the 

 flower and more highly magnified, a, one of the anthers, the slit showing where the pol- 

 linium has been withdrawn: /\ the stigma; c, opening into the nectary at the base of the 

 labellum. B, The two pollinia still more highly magnified; a, the mass of agglutinated 

 pollen grains; b, the sticky disc at the opposite end of the pollinium. 



next flower is visited, they are brought into contact with the 

 sticky stigmatic surface, and some of the pollen is almost inev 

 itabl.y deposited upon it. By flying thus from flower to flower, a 

 considerable number may be fertilized before finally the pollinia 

 are brushed off, or their pollen exhausted. 



While, as has been stated, cross fertilization is the law, 

 there are a few remarkable instances in which flowers ap- 

 pear to be constructed with special reference to self-fertiliz- 

 ation. Some Violets and Polygalas, for example, produce, 

 besides showy flowers that are visited by insects, others that are 

 inconspicuous, closed, and often partly concealed beneath the 



