POLLEN. 



336 



POLLEN. 



next flower, B, wliere the upper portion 

 of the tongue and mouth becomes dusted 

 with the pollen from the anthers, and the 

 pollen dust that was secured from the other 

 tlower A will just reach the stigma in the 

 flower B. The pollen dust that was received 

 from the flower B will just reach the stigma 

 in the flower A. There is another significant 

 • and interesting fact, that the pollen gran- 

 ules of B are too large to be received in the 

 stigma of B, but just right to go in the stig- 

 ma of A. Thus we see how nature has cun- 

 ningly devised a scheme of what is called di- 

 morphic cross-fertilization. In other words, 

 she has so planned it that the pollen of the 

 same flower can not fertilize its own stigma, 

 hence we see the necessity of some insect of 



brings to it from the anthers of A of the 

 other Idossom of the same plant. It will be 

 apparent in this particular rase, unless in- 

 sects, particularly the bee, cany the pollen 

 from A to B, there will be no fertilization of 

 the plant, and the bloom will die without 

 fruit. 



In Fig. 5 we have another case no less 

 remarkable of a near relative of rhodo- 

 dendron and azaleas. The filaments bear- 

 ing the anthers are curved downward, the 

 anthers themselves appearing to be held 

 in little pockets of the flower. Apparently 

 they have no power of their own to release 

 themselves. But a bee comes along, alights 

 on the blossom, and as it reaches around 

 for the nectar jars these filaments loose. 



Fig. 5.— KaliMIA Latifolia, Order Ericacea. 

 Flowering- Branch. B, Expanded Flower— ap. Anther Pocket. C, Section ot Ex- 

 panded Flower — ap, ap. Anther Pockets; s. Stigma; a. Anther (free): pg. Pollen 

 Grains in Shower; ca. Calyx. D, Section of Flower Bud— ap. Anther Pocket. E, 

 Stamens, more Enlarged— a, Antiier; po, Pores; pQ, Pollen Grains; /, Filament. 

 —After- Cheshire. 



just about the right size, as the bee, of ex- 

 actly the- same tongue length that the bee 

 has. Let us take another example. 



In Fig. 4 we have a very pretty example 

 of the fine honey-plant willow-herb; here the 

 pollen of the anthers is sterile to the pistil 

 or stigma of the same flower. At A, Fig. 4, 

 we notice that the stigma, or the style, 

 rather, as at s, is turned backward away 

 from the anthers at a. At this stage the 

 pollen at the anthers is ripe. A bee comes 

 along, dusts itself over the pollen in the act 

 of securing nectar, and then passes over to 

 B of a fiower of the same species. Here 

 the pollen is gone from the antliers, but the 

 l)istil has straightened out and the stigma 

 is ripe to receive the pollen that the bee 



when they immediately fly upward, dust- 

 ing the bees with pollen. This pollen now 

 on the bee may fertilize the stigma or 

 pistil of B; but as the bee goes frorh flower 

 to flower the pollen is mixed for it re- 

 leases all the anthers, so that other insect 

 visitation will continue on the process of 

 cross-pollination. We have familiar cases 

 of these anchored-down anthers in the rho- 

 dodendrons, azaleas and some of the swamp 

 laurels. They are all honey-plants, but the 

 honey is said to be poisonous. 



In Fig. 6 we have a familiar blossom of 

 the pea and bean, or technically known as 

 papilionaceous flowers. At C we notice em- 

 bryo bean or pea pod. At a we see the an- 

 thers and s the stigma. This whole thing is 



