476 



Dansk Botanisk Arkiv, Bd. 3. Nr. 1. 



As always in the case of the Farn, of the Rhodomelaceæ it 

 is from the second joint of the young trichoblasts that the procarp 

 originates. The lowermost joint of the trichoblast becomes po- 

 lysiphonous, too, while the upper end of the trichoblast soon 

 dies away. 



Fig. 432 a shows a quite young procarp. Fig. 432 b a more 

 advanced stage at the moment of fecundation. We see here the 

 four-celled carpogonial branch from which the long thin trichogyne 

 (specimens have been found in which the trichogyne has twice 



Fig. 432. Lophosiphonia cristata Faikenb. 

 a, quite young procarp. b, more developed procarp in the stade of ferti- 

 lization, c, upper end of erect filament with cystocarp. d, part of basal 

 creeping filaments with rhizoids ending in large roundish discs, 

 (a and b, about 260:1; c, about 150:1; d, about 60:1.) 



the length of the one drawn in the figure) protrudes; two 

 spermatia are fixed to its upper end. The fully developed cysto- 

 carp (Fig. 432 c) is oblique urceolate with a rather broad opening 

 in its upper end. It is about 200 ^ long and 170 fi broad. 



The tetrasporangia have been found by Falkenberg and I 

 refer to his description (1. c, p. 500). The tetrasporangia are form- 

 ed one in each segment in the upper end of the erect filaments 

 and in adventitious short branchlets, of which several were pre- 

 sent in the specimens found. They are spirally arranged. 



The specimens with cystocarps and tetraspores were found 

 in the month of January. Together with Herposiphonia tenella, 

 Laurencia and blue-green algæ it formed low dense crusts upon 

 the rocky shore of Water Island at St. Thomas. 



