176 AMARYLLTDE^, IRIDE^. [chap. 



highly irritable ; in the present species the right-hand 

 one is apparently functionless ; but the moment the 

 insect touches the left-hand one, the excitement is 

 conveyed along it, the membrane retaining the polli- 

 nium is ruptured, and the latter is immediately jerked 

 out of the flower, by its own elasticity, with consider- 

 able force, with the viscid disk {d) foremost, and in such 

 a direction as to come in contact with the head of the 

 insect which had touched the antenna. On subse- 

 quently visiting a female flower the insect brings the 

 pollen into contact with the stigma. 



AMARYLLIDE^. 



This beautiful order contains three British genera ; Narcissus, Galan- 

 thus (the Snowdrop), and Leucoium. 



The Snowdrop is ptobably not a true native of this country, but has 

 long been naturalised in many parts. It is sweet scented, and melliferous ; 

 as the flower hangs down, the honey is perfectly protected from rain by 

 the leaves of the perianth. The flower remains open from about ten in 

 the morning till four in the afternoon, when it closes for the night. 

 The pistil is white, except at one part a little above the middle where 

 it is tinged green, a character more marked in the next genus, 

 Leucoium. 



IRIDE^. 



We have five British genera of this group ; Iris, Gladiolus, Sisyrin- 

 chium, Trichonema, and Crocus. 



Iris pseudacorus L. secretes honey. It is fertilised by humble bees, 

 and according to Miiller, still more frequently by Rhingia. The flowers 

 are large and showy, the three outer perianth-segments large, spreading 

 and refliexed, the three inner ones much smaller and erect. The stigmas 

 are three in number, enlarged, and each with an appendage resembling a 

 petal, which arches over the corresponding stamen and outer segment of 

 the perianth. In order to reach the honey, insects have to force thei.- 

 way between this segment and the over-arching stigmatic leaf. 



