334 



THE MICROSCOPE AND ITS REVELATIONS. 



FIG; 2T3. 



the conceptacles in little gelatinous masses on their orifices; for if some 

 of the spores which have been set free from the olive-green (female) 

 receptacles be placed in a drop of sea-water in a very shallow cell, and a 

 small quantity of the mass of antherozoids, set free from the orange- 

 yellow (male) receptacles, be mingled with the fluid, they will speedily 

 be observed, with the aid of a magnifying power of 200 or 250 diameters, 

 to go through the actions just described; and the subsequent processes of 

 germination may be watched by means of the ' growing slide. ' l The 

 winter months, from December to March, are the most favorable for the 

 observation of these phenomena; but where Fuci abound, some indi- 

 viduals will usually be found in fructification at almost any period of the 

 year. Even in the Fucacece, according to recent observations, a multi- 

 plication by 'zoospores,' like that of Ulvacece ( 245), also takes place; 

 these bodies being produced within certain of the cells that form the 

 superficial layer of the frond, and swimming about freely for a time after 

 their emission, until they fix themselves and begin to grow. That they 



are to be considered as gemma 

 (or buds), and not as genera- 

 tive products, appears certain 

 from the fact that they will 

 vegetate without the assist- 

 ance of any other bodies; 

 whereas the antherozoids of 

 themselves never come to any- 

 thing; while the octospores 

 undergo no further changes, 

 but decay away (as M. Thuret 

 has experimentally ascertain- 

 ed) if not fecundated by the 

 antherozoids. 



330. Among the Rhodo- 



r-mece, or red Sea-weeds, 

 , we find various simple 

 but most beautiful forms, 

 which connect this group with 

 the more elevated Proto- 



phytes, especially with the 

 family Clmtoplioracece ( 256); 

 such delicate feathery or leaf- 

 like fronds belong for the 

 most part to the family Cera- 

 miacece, some members of 

 which are found upon every 

 part of our coasts, attached 

 either to rocks or stones or to larger Algae, and often themselves affording 

 an attachment to Zoophytes and Polyzoa. They chiefly live in deeper 

 water than the other sea- weeds; and their richest tints are only exhibited 

 when they grow under the shade of projecting rocks, or of larger dark-co- 

 lored Algae. Hence in growing them artificially in Aquaria, it is requisite 

 to protect them from an excess of light; since otherwise they become un- 

 healthy. Various species of the genera Ceramium, Griffithsia, Calli- 

 thamnion, and Ptilota, are extremely beautiful objects for low powers, 

 when mounted in glycerine jelly. The only mode of propagation which 



1 A shallow cell should be used, so as to keep the pressure of the thin glass 

 from the minute bodies beneath, whose movements it will otherwise impede. 



Arrangement of Tetraspores in Carpocaulon mediter- 

 raneum : A, entire plant; B, longitudinal section of 

 spore-bearing branch. (N.B. Where only three tetra- 

 spores are seen, it is merely because the fourth did not 

 happen to be so placed as to be seen at the same view.) 



