108 BRITISH FLOWERING PLANTS chav. 



as only to touch them at the base and summit. An 

 eminent French entomologist, M. Fabre, has pointed out 

 that while bees eat their way through the tough cocoon, 

 if this is enclosed in paper — even tissue-paper — they 

 perish, not thinking of eating through a second, even 

 much thinner, obstacle. It has already been mentioned 

 more than once (see p. 64) that bees often rob tubular 

 flowers of their honey by eating through the base of the 

 tube, and it has occurred to me that the inflation of the 

 calyx thus tends to protect the honey. I say tends, 

 because the device is not in all cases successful. The 

 legitimate visitors are butterflies, moths, and the humble 

 bees with long probosces. Kerner doubts whether 

 inflated calyces are in all cases intended to protect the 

 honey, because the proboscis of the average humble bee 

 is at least 8 mm. in length, and the distance between the 

 calyx and corolla is generally less. But his reasoning is, 

 I think, fallacious. In the first place, inside the calyx is 

 the corolla, and this the mandible could not reach. 



With us the plant is generally glaucous, and throws 

 ofl" moisture, except in the angles between the leaves, 

 where rain collects, and is no doubt absorbed. There is, 

 however, a variety — jjuherida- — with short curly hairs, 

 and in the hot dry climate of the south the plant 

 develops a thick covering of hair, probably as a pro- 

 tection against too rapid transpiration. 



S. nutans (Nottingham Catchfly). — This is also a 

 protandrous, nocturnal moth -flower. The life of the 

 flower lasts three days, or rather three nights. The 

 stamens are ten in number, arranged in two sets, the 

 one set standing in front of the sepals, the other in 

 front of the petals. Like other night flowers, it is 

 white, and opens towards evening, when it also becomes 

 extremely fragrant. The first evening, towards dusk, 

 the five stamens in front of the sepals grow very rapidly 

 for about two hours, so that they emerge from the 

 flower ; the pollen ripens, and is exposed by the burst- 

 ing of the anther. So the flower remains through the 

 night, very attractive to, and much visited by, moths. 



