1919 



(JLKAXIXOS IX HKK CVl.TVllK 



253 



one of the most remarkable eases of how 

 Xature has schemed lo bring about cross- 

 fertilization. This is 

 what is Jviiown as u 

 dimorphic flower, thai 

 is to say. there are two 

 forms of flowers on the 

 same jilant. At A the 

 stiirma of the female 

 portion reaches iij) to 

 the mouth of the llow- 

 er-tube. The anthers, 

 or male portion, aj)- 

 l)eiir about half way 

 down the flower-tube 

 as at a. At B we have 

 just the reverse: the 

 stiijma stands about 

 h;df way down the 

 tlower-tube while the 

 anthers are clear at the 

 to]). The fiower-tube 

 itself is supposed to l)e 

 about the dei)th of the 

 reach of a bee's tongue. 

 .\ l)ee comes to A, 

 reaches down at the 

 |)oint o for its nectar. 

 The anthers half u)) 

 dust the tongue at a 

 point about lialf way 

 uj) its length. After 

 the bee has secured its 

 coveted sweet, it jiasses 

 to the next flower, li, 

 where the u|)i)er i)or- 

 tion of the tongue and 



moutli becomes dusted with the pollen from 

 the anthers, and the jwllen dust that was 

 secured from the other flower A will just 

 reach the stigma in the llower li. The i)ol- 

 len dust that was received from the llower 

 I? will just reach the stigma in the flower .\. 

 There is another signiticant and interesting 

 fact, that tlie i)oilen granules of H are too 

 larije to be received in the stigma of li, but 



Kic. .").— Kalmia l.ATiFOT.iA. ( irdei' A'; 



Ki'ii.oiurM AN(;rsTiFOLiUM (KosEBAY WILLOW IlEKB) , ( inler On<(- 

 iiracece. — Gray. 

 just right to go in the stigma of A. Thus 

 we see how nature has cunningly devised a 

 sclieme of what is called dimorphic cross- 

 fertilization. In other words, she has s;) 

 l)lanned it that the pollen of the same flower 

 can not fertilize its own stigma, hence we 

 see the necessity <»f some insect of just about 

 the right size, as the l^ee. of exactly tlie 

 same tongue lengtli that the bee has." Let 

 us take another 

 /)o example. 



In Fig. 4 we 

 have a very i)ret- 

 ty example of the 

 fine honey-iilant 

 willow-herb: here 

 the pollen of the 

 anthers is sterile 

 to tlie ])istil or 

 stigma of the 

 same llower. At 

 A, Fig. 4, we no- 

 tice that the 

 stigma, or the 

 style, rather, as 

 at s, is turned 

 baclcward away 

 from the anthers 

 at a. At this 

 stage the pollen 

 at the anthers is 

 ri))e. Al)eecomes 

 along, dusts itself 

 -CJiexiih-p. over the jxiUen 



