PRACTICAL PART. 



CLASS I 



Hippuris vulgaris. 



Kazenzahl, Weisse Seetannc, Tannwcdel. — Fren. Pesse com^ 

 mime. — Eng. Mare's-tale, Paddow-pipe, — Ital. La Corre- 

 g iola femmina. — S wed. Hastswants. 



There are few of the higher plants which have so simple a 

 structure as this, or which have so much simpUcity in the re- 

 lations of the essential parts. 



In deep ditches, in standing and running waters, there 

 arises in spring a round stem, from one to two feet above the 

 water, straight, perpendicular, almost stiff (41.), and simple 

 (45.) Its colour is reddish ; and its circumference is iu size 

 about that of the quill of a pigeon's or hen's feather. It is 

 also jointed (40.), and shoots out under the water, first, ho- 

 rizontal fibrous roots, and, next, pellucid, linear-lanceolate 

 leaves. On dissection, we discover in the circumference a 

 compound cellular texture, with distinct regular interstices 

 (299.) ; and in the centre there is a firm cord, composed of 

 spiral vessels and sap-tubes (280.) 



Above the water, there spring from each joint of tlie stem 

 conmionly from eight to ten leaves, arranged in a circle (36.) ; 

 sonictinies also, especially under the water, fasliioned into a 

 s}>iial shape (37 ) horizoiitul, Iliu-ai-lanccolale, somewhat oh- 



