GENERATION IN SPBLEROPLEA AND (EDOGONIUM. 333 



tlie lower part of fig. 12, thenceforward constituting true Spores. 

 These undergo further changes whilst still contained within their 

 tubular parent-cells ; their colour changing from green to red, and 

 a second investment being formed within the first, which extends 

 itself into stellate prolongations, as seen in fig. 13 ; so that, when 

 set free, they precisely resemble the mature Oo-spores which we 

 have taken as the starting-point in this curious history. Certain 

 of the filaments (fig. 14), instead of giving origin to spores, have their 

 annular collections of endochrome converted into Antherozoids, 

 which, as soon as they have disengaged themselves from the 

 mucilaginous sheath that envelopes them, move about rapidly in 

 the cavity of their containing cell (a, b) around the large vacuoles 

 which occupy its interior ; and then make their escape through 

 apertures {c,d) which form themselves in its wall, to find their way 

 through similar apertures into the interior of the spore-bearing cells, 

 as already described. These Antherozoids are shown in fig. 15, as 

 they appear when swimming actively through the water by means 

 of the two motile filaments which each possesses. The peculiar 

 interest of this history consists in the entire absence of any special 

 organs for the Generative process, the ordinary filamentous cells 

 developing Spores on the one hand, and Antherozoids on the other ; 

 and in the simplicity of the means by which the fecundating process 

 is accomplished. — A curious variation of this process is seen in 

 (Edogonium; for whilst the Oo-spores are formed within certain 

 dilated cells of the ordinary filament (Fig. 154, i), and are fertilized 

 by the penetration of antherozoids (2), these antherozoids are not the 

 immediate product of the sperm-cells of the same or of another 

 filament, but are developed within a body termed an ' Andro- 

 spore' (5), which is set free from within a germ-cell (4), and 

 which, being furnished with a circular fringe of cilia, and having 

 motile powers, very strongly resembles an ordinary Zoospore. This 

 Andro-spore, after its period of activity has come to an end, attaches 

 itself to the outer surface of a germ-cell, as shown at 1, b ; it then 

 undergoes a change of shape, and a sort of lid drops off from its free 

 extremity, as seen in the upper part of 1, by which its contained 

 Antherozoids (2) are set free ; and at the same time an aperture is 

 formed in the wall of the cell containing the Oo-spore, by which 

 the antherozoid enters its cavity, and fertilizes its contained mass by 

 dissolving upon it and blending with it. This mass then becomes 

 invested with a thick wall of its own ; but even when mature (3) it 

 retains more or less of the envelope derived from the cell within 

 which it was developed.* It is probable that the same thing 

 happens in many other Confervaceae, and that some of the bodies 

 which have been termed Micro-gonidia are really Andro-spores. The 

 offices of these different classes of reproductive bodies are only now 

 beginning to be understood ; and the inquiry is one so fraught with 



* See Pringsheira in "Ann. des Sci. Nat.," 4ieme Ser., Botan.. Tom. 

 v. p. 187. 



