CH. iv] THE FROGBIT 43 



favourable material for observing the rotation of protoplasm. 

 The roots, with their thick mat of root-hairs, get much tangled 

 together, and the countless stolons growing in every direction 

 are similarly enlaced, with the result that Hydrocharis forms a 

 thick carpet which can scarcely be submerged even by rough 

 movements of the water. Detritus collects between the root- 



(/i) ' ^^::r--^3 



-ax-, 



Fig. 24. Hydrocharis Morsus-ranae, L. A, dissection of a summer bud, just open- 

 ing; (i)-(vi) show the result of removing successive members. B (i), a bud of which 

 one leaf has unfolded ; B (ii) shows the result of removing the outer scale leaves 

 and the stipules of the first foliage leaf; ax^ and ax 2, stolons terminating in first 

 and second bud; A, A- A, successive fohage leaves; 5^1, st^, stipules belonging to 

 /i and /a; s and s, outer scale leaves; r^ and r^, roots belonging to first and second 



bud. [A. A.] 



hairs and may serve as a source of food. This colonial mode of 

 growth offers serious resistance to the intrusion of other water 

 plants. 



The bud, in which each stolon terminates, is enclosed in two 

 delicate, membranous scales (s and s Fig. 24 J (i)). These are 



