loo Flowers and their Unbidden Guests. 



parts of the variously-contorted perianth or parts of 

 the andrcecium and gynaecium, and in no few instances 

 parts of several different floral whorls contribute to 

 their formation. 



Amongst the best known of the flowers which 

 present this kind of formation may be mentioned- 

 Corydalis, Fumaria, and Diclytra, as also many with 

 what are known as "personate" corollas, such as 

 Antirrhinum, and many species of Linaria (Plate II. 

 fig. 41, Linaria alpina). In these plants the lower lip 

 of the corolla is strongly curved, and has an arching 

 protuberance, the convexity of which is in immediate 

 contact with the upper lip, so that the entrance to the 

 flower is completely closed. An insect that alights on 

 the lower lip cannot possibly get at the nectar in the 

 spur, unless, by forcible pushing and shoving, it causes 

 a depression of this lip. 



In many cases the over-arching is brought about by 

 epiblastemes or outgrowths of the corolla, which assume 

 the form of humps ; and which, being closely approxi- 

 mated to each other, must be pushed asunder by force 

 before an insect can insert its proboscis into the nectar- 

 cavity. The Gynoglossum pictum, represented in Plate 

 II. fig. 60 in longitudinal section, is an instance of this. 

 Sometimes instead of humps there are merely scales or 

 valve-Uke processes, which are given off by the corolla, 

 and project into the interior of the flower, so as to 

 divide it, as with a diaphragm, into two chambers, in 



