462 BULLETIN OF THE BUREAU OF FISHERIES. 



crop varies within the given limits in different summers but is fairly constant in any one summer. At 

 Beaufort and Naples, and probably elsewhere, the sexual cells are liberated at or a little before dawn. 



In spite of this great difference in the production of their crops, the close morphological similarity 

 of the Beaufort plants to those of Europe seems to preclude the placing of these in a separate species. 

 The facts mentioned above, however, show that the characters which have been used to separate certain 

 speciesthe size and width of plants and the acuteness of the apices are not by themselves safe 

 characters for specific distinctions. 



The studies of Williams (1904, 19043) and the cultures of Hoyt (1910) have shown that in this 

 species the sexual and asexual generations alternate with each other in regular succession. 



Division IV. RHODOPHYCE^E Ruprecht. 



Rodospenneze, Harvey, 1852, p. i. 

 Florideae, Farlow, 1882, p. 106. 

 Florideae, De Toni, 1897, p. i. 



RED ALG^. 



Algae colored rose, crimson, or purple, less often violet, olivaceous, green, or blackish, 

 containing in their cells endochrome composed of chlorophyll, and a characteristic red 

 pigment (phycoerythrin) mixed with other pigments; endochrome contained in definite 

 chromatophores ; thallus varying greatly in size and form, composed of segmented, 

 separate, or more or less coalescent filaments; cells containing one or more nuclei. Mul- 

 tiplication asexual or sexual. Asexual propagation usuallyby spores, sometimes by brood 

 cells or brood buds; spores usually produced four (tetraspores), sometimes one (mono- 

 spore), two, or many in a sporangium, at first naked, later inclosed by a membrane, 

 usually nonmotile, in some cases possessed for a time of slight amoeboid movement, but 

 apparently always passively distributed; sporangia external or immersed, distributed over 

 the thallus or borne on more or less specialized portions. Sexual reproduction by the 

 fusion of dissimilar male and female gametes borne on the same or different individuals. 

 Male gametes (spermatia) naked, nonmotile, produced one or many in a more or less 

 specialized antheridium, discharged into the water and passively transported; antheridia 

 usually external, sometimes immersed, borne on specialized or unspecialized portions of 

 the thallus, in the Bangiales formed by the transformation and division of ordinary 

 vegetative cells. Female gametes occurring singly within special organs, never escaping 

 free into the water. These organs, usually immersed, sometimes external, are, in the 

 Bangiales, formed by the direct transformation of swollen vegetative cells; in the Florideae 

 they are borne at the ends of short, usually three or four celled filaments 

 (carpogenic branches) each organ (carpogonium) consisting of a swollen basal 

 portion and a hairlike, apical prolongation, the trichogyne. Associated with these 

 organs in reproduction there are, in most orders of the Florideae, special cells, 

 auxiliary cells, which are either joined with the carpogonium in a common structure, 

 the procarp, or occur separately in the thallus more or less near the carpogonia. In 

 the fusion of male and female gametes a spermatium is floated to the trichogyne and 

 fuses with this, the male nucleus passing down and fusing with the female nucleus in 

 the swollen basal portion of the carpogonium. This fertilized egg cell then either 

 directly produces tufts of spore-bearing filaments (gonimoblasts), or, in most orders, 

 gives off longer or shorter filaments bearing the fertilized egg nucleus or some of its 

 descendants, these filaments fusing with the auxiliary cells, and the auxiliary cells then 

 giving rise to spore-bearing filaments. The fruits thus produced (sporocarps) are often 

 inclosed by a more or less specialized sterile jacket, the whole structure constituting the 



