246 SEEDLINGS OF AQUATICS [CH. 



later roots borne on the hypocotyl and plumule are negatively 

 geotropic. 



An exceptional case is that of Littorella lacustris^^ in which 

 the seeds remain in situ. The gynaecea are borne close to the 

 axis, between the leaves, near the base of the little plant. On 



FIG. 159. Zannichelliapolycarpa, Nolte. A, L.S. fruit (x 15) ; a = stigma; 6 = coty- 

 ledon; h = hypocotyl; A = vascular tissue; r = primary root; p = plumule. 

 B, cotyledon emerging from fruit (x 6). C, seedling (x 4); rh = root hairs. 

 [Raunkiaer, C. (1896).] 



the death of the parent, the fruits are left surrounded by the 

 decaying remains; they germinate where they were produced, 

 only being dislodged in rare instances. The somewhat similar 

 behaviour of Cymodocea aequorea has been discussed on p. 127. 



1 Fauth, A. (1903). 



