Protection of Gentians. 43 



I have also noticed collections of water above the 

 connate bases of the opposite leaves in the large gentians 

 of the Alps, especially in OeMtiariM lutea, pannonica, 

 and piTictata. The quantity of water in the sheaths 

 formed by the leaves is in this case only small ; still 

 it is quite sufficient to debar wingless insects from 

 access to the flowers. If ants are placed on the 

 stem of such a gentian, they run up and down it ; 

 and each time that they come to one of the little 

 pools of water in the sheath-like basilar expansion 

 of the pair of leaves which encircle the internode, 

 they turn back; until at last, after vain journeyings 

 up and down, they let themselves fall to the ground. 

 Inasmuch as the receptacles formed by the leaf-bases 

 of these gentians are very shallow, and the quantity 

 of water which they contain but small, the effect of 

 evaporation is much greater than in the earlier-men- 

 tioned cases. These gentians, however, grow in places 

 where at the period of blossoming there is a very 

 abundant dew on, rainless days, and the leaves project 

 horizontally, with their concavities turned upwards, 

 just like so many buckets set out on purpose to catch 

 it. Thus the water required to fiU the basal leaf- 

 receptacles is never wanting ; and on no single occasion 

 when I examined such a gentian did I fail to find 



leaves of the teasel. He even alludes to nectar, as one of the 

 treasures to be guarded in this kind of way, although he was not 

 of course aware of the true relations existing between flowers and 

 insects. — (See Loves of the Plants, note 6.)" — ^Editob.] 



