2 30 



Minnesota Plant Life. 



honey is secreted. In order to ol)tain the honey it must thrust 

 its hill aloni;- the efroove where the two adhesive discs are sit- 

 uated. When the insect has sipped the drop of honex- which 

 it seeks. ha\iny" heen drawn to it hy the perfume and color of 

 the tlow er. it Hies away, carryins.;' with it the two ])ollen- 

 masses. one on each side of its hill. Innnediatelv after the 

 insect lea\"es the Hower the two pollen-masses hend forward 

 and the next flower visited receives these pollen-masses fairly 

 on the sticky end of the stigma, where the pollen-spores ger- 

 minate and give rise to the male orchid i)lants. From this sec- 

 ond tiower the moth carries 

 awa}- a fresh pair of ])ollen- 

 masses. 



Such ver}' woiiderful and 

 l)erfect devices secure what is 

 termed cross-pollination. The 

 pollen is taken from one flower 

 and carried to the stigma of 

 another upon another ])lant, 

 thus apparently i n s u r i n g a 

 greater vitality and l)readth of 

 e X ]:> e r i e n c e in the emhryo 

 plantlets which are to he de- 

 \eloped in the seeds. A va- 

 rietv of such mechanical de- 

 vices are employed hy ])lants. 

 Those of the orchids with their 

 automatic adhesi\e discs and curving-stalked pollen-ma.sses be- 

 ing amo!ig the most marvelous in their perfection. Yet it may 

 he said that the orchids are over-relhied and almost too per- 

 fect. The exactness of the machine is indeed so great that the 

 chances against its working are a])])arently intniitesimal. The 

 seeds, however, are so small and the emhryo plantlets are pro- 

 vided with so little nutriment with which to enter ui)on their 

 indei)endent life that the great majority of them must certainly 

 ])erisl). The ureiiids, in their (le\eli ipnient. ha\e given their at- 

 tention, so to si)eak. to the elalx >rati< m of highly complicated 

 methods of cross-])i>llinalion. hut ha\e at the same time neg- 



l-'iG. 104. wild orchis. .-Xfter lirittoii am 

 Hrown. 



