329 



such long stigmas on lateral shoots and supposed them to be 

 fecundated below water, though he had not then found submerged 

 male flowers. 



Kncth (1899 p. 380) and Warnstorff (1896 p. 27) describe 

 C. verna and C. stagnalis as anemophilous and protogynous, 

 speaking of the sprout; in the small inflorescence of the axil, 

 found in strong and well nourished specimens of these two 

 species, the male flower is earlier developed than the female 

 one, Hegelmaier (1864 p. 35); according to Ludwig (1881 p. 9) 

 they are hydro-entomophilous. 



In contradiction to this Hegelmaier (1864 p. 59) found C. 

 stagnalis sterile, if quite submerged, and he supposes that 

 such is also the case with C. hamulata (1. c. p. 56). According 

 to Kerner^ "the stamen of these flowers did not open at all". 

 In Botany of the Færoes Ostenfeld (1908 p. 938) writes of C. 

 hamulata, that it is pollinated by the wind but capable of self 

 pollination, when the water is high and the flowers submerged, 

 this accounting for the regularity of fruiting. Some plants of 

 this species from Mödruvellir and from Vallanes, Iceland, bear 

 fruits; only linear leaves being present, the plants have pro- 

 bably been submerged. In a fruit from Vallanes, placed in the 

 axil of a deeply emarginate leaf, 8*5 cm. from the top of the 

 shoot, the embryos were developed, which shows, as far as 

 might be concluded from a herbarium specimen, that Hegel- 

 maier is not right in supposing that submerged fruiting does 

 not take place. 



The fecundation of the more simply built flowers of С 

 autumnalis as well as those of other Pseudocallitriche is eff'ected 

 below the water. It has been studied by Jonsson (1884 p. 21); 

 the pollen, the specific gravity of which is less than that of the 

 water, is filled with oil. 



■ As in temperate regions the abundance of fruits is largest 



' quoted from Knith's Blüthenbiologie. 



