42 OPIIRE.E. Chai-. I, 



lower and first opened flowers. But this statement is 

 coiii})letely contradicted by my observations previously 

 given, from wliich it follows that very many of the 

 upper flowers are fertilised ; for instance, on a spike 

 of 0. pyramidalis with between fifty and sixty flowers, 

 no less than forty-eight had their pollinia removed. 

 Nevertheless, as soon as I learnt that Delpino still be- 

 lieved in Sprengel's view, I selected during the un- 

 favourable season of 1875 six old spikes of 0. maculata, 

 and divided each into halves, so as to observe whether 

 many more capsules were produced by the lower tlian 

 by the upper half. This certainly was not always the 

 case ; for in some of the spikes no difference could be 

 detected between them ; in others there were more cap- 

 sules in the lower, while in others there were more in 

 the upper half. A spike of 0. lyyramidalis examined 

 in the same manner produced twice as many capsules 

 in the upper as in the lower half. Bearing in mind 

 these facts and others before given, it apj^ears to me 

 incredible that the same insect should go on visiting 

 flower after flower of these Orchids, although it never 

 obtains any nectar. Insects, or at least bees, are by 

 no means destitute of intelligence. They recognise 

 from a distance the flowers of the same species, and 

 keep to them as long as they can. When humble- 

 bees have bitten holes through the corolla, as they 

 often do, so as to reach the nectar more easily, hive- 

 bees immediately perceive what has been done and 

 take advantage of the perforations. When flowers 

 having more than a single nectary are visited by many 

 bees, so that the nectar is exhausted in most of them, 

 the bees which afterwards visit such flowers insert 

 their proboscides only into one of the nectaries, and 

 if they find this exhausted, they instantly pass on to 

 another flower. Can it be believed that bees which 



