MONOCOTYLEDONS. 281 



the three fan-like stigmas, with more or less toothed or 

 frilled edges, continued below into the style; cut open the 

 flower-tube and trace the slender style right down. Both 

 the style and the flower-tube arise from the top of a swelling, 

 the ovary; cut the ovary across and notice the numerous 

 " young seeds " arranged* in two longitudinal rows on the 

 inner side of each of the three ovary-chambers. Below the 

 ovary is the flower-stalk ; the bracts spring from this stalk, 

 just below the ovary. 



Close observation of a flower day by day will show that the 

 lobes spread out in the daytime and move inwards at night, 

 thus causing the opening or closing of the flower. The flower 

 opens when exposed to light, sufficient warmth, and dry air, 

 whilst its closing may be caused by coldness or dampness of 

 the air as well as by darkness. The movements of opening 

 and closing can, by careful measurement, be shown to be 

 caused by the outer sides of the perianth-lobes growing faster 

 (closing movement) or more slowly (opening movement) than 

 the inner sides. What are the advantages to the flower of 

 this power of opening or closing ? What other plants, grow- 

 ing wild or in gardens, have flowers which open on bright 

 days and close on dull or wet days and at night ? For how 

 many days does a Crocus flower last ? 



It is easy to discover that the anthers open by two slits, 

 shedding the pollen outwards, i.e. away from the centre of 

 the flower, that this happens while the stigmas are in contact 

 with each other, and that a day or two after the anthers have 

 opened the three stigmas separate and spread out, one opposite 

 each inner perianth-lobe. Do you see how this helps in 

 promoting cross-pollination ? The Crocus flowers are visited 

 by bees, butterflies, and moths. 



The Crocus contains honey in abundance, as can easily be 

 seen by opening up the perianth-tube ; the honey, produced 

 by glands in the partitions between the three ovary- chambers, 

 rises up the tube and can be sipped by bees entering the 

 flower. The bee stands on the perianth -lobes and pushes its 

 head into the funnel-like mouth of the tube, seeking for the 

 honey, and in doing this it touches the stigmas (if these have 

 spread out) and then the stamens. If, however, cross-pollina- 

 tion fails to occur, the stigmas may curl over and touch the 

 anthers, bringing about self-pollination. 



