BY E. IIAYILAXD. 615 



o£ the ground and then placing it in a deeper part of the stream 

 it has floated erect, with its flowers above the water. 



"We have an equally efficient provision made in Vallisneria 

 spiralis, a dioecious plant growing freely in some of our rivers. 

 In that plant, the pistiline flowers are borne on long spiral 

 peduncles, which stretch out as the water increases in depth ; 

 always keeping them on the surface ; while the plant bearing the 

 staminate flowers, becomes detached from the soil and floats 

 about on the water, preserving the pollen from contact with it. 

 The construction of the flower of TJtricularia diclwtoma is exceed- 

 ingly interesting. The corolla is of the richest purple, having a 

 brilliant gold coloured spot or eye at the base of the lower lip. 

 As I have already said, it is monopetalous, but divided down to 

 the spur at its base. The upper lip is exceeding small, perhaps 

 not more than two lines ; while the lower lip is broadly semi- 

 circular, spreading like an open fan, and half to three quarters 

 of an inch wide. The narrow portions or claws, of the two lips 

 are long and concave, and lying closely together form a tube 

 enclosing both stamens and pistil. The mouth of this tube is 

 closed by the appendage or palate attached to the lower lip ; so 

 that both stamens and pistil are quite imprisoned. The two 

 stamens are attached to the claw of the upper lip, and their 

 filaments are so curved that the broad anthers are brought closely 

 together, edge to edge ; and thus form a shield in front of the 

 stigma, but with their backs to it, and opening and shedding their 

 pollen away from it. Upon examining the spur at the base of 

 the corolla, it wall be found sweet to the taste, leaving little doubt 

 that its purpose is to secrete or contain nectar. 



The rationale of this arrangement, appears to me to be this 

 — But I must crave pardon for a little repetition. The lower lip 

 standing out horizontally as a broad flat stage, offers a landing 

 place to an insect ; just as the labellum of an orchid does. The 

 small upper lip projects a very short distance over the surface of 

 the lower one, and is raised above it at just such an angle as to 



