32 Mr. H. J. Carter on Fecundation in (Edosronium 



o^ 



the first being dioecious and polyandronitie (to coin more new 

 terras for the occasion), the second monoecious and diandronitic, 

 and the third monoecious and triandronitic ; while these features 

 being only present at the time of sporing, shows that (Edogonium 

 can only be successfully studied for description during this 

 period ; and therefore holds out the hope that many other spe- 

 cies of this interesting genus — now, as M. Thuret has stated 

 (Ann. des Sc. nat. 1850), in almost inextricable confusion from 

 their synonymy — may receive elucidation through similar means. 



Fecundation. 



Very soon after seeing Prof. Pringsheim's figure of the spo- 

 rangium of (Edogonium tumidulum^j I met with some spore-cells 

 of (E. dioicum, above described, in which the aperture pointed 

 out by this talented observer was present ; but it being late in 

 the season (October), I could not obtain more for following up 

 the process of impregnation, and so deferred it until this year. 

 Meanwhile the first part of Pringsheim's description and illus- 

 trations of the act itself, in (E. ciliatumf (the only part that I 

 have been able to obtain), reached me, and I was thus well 

 prepared to take advantage of the sporing of (Edogonium here, 

 which, in consequence of the tanks having been filled by ^' the 

 rains," for some time past, is now again taking place (Sept. 

 1857). 



The first species obtained for observation was (E, dioicum, in 

 which the formation of the resting-spore and micropyle takes 

 place in the following way : viz. when the spore-cell has become 

 fully inflated, and the green gonimic contents uniformly and 

 densely spread over its internal surface (fig. 1, a), a small, 

 roundish, semi-transparent area makes its appearance in some 

 part of the upper or prominent portion ; the cell-wall now begins 

 to open transversely opposite this point, in the direction of the 

 margin of the striated portion, producing a short crevice, through 

 the widest portion of which the internal layer or protoplasmic 

 sac is projected in a thin globular form with a constricted base ; 

 this globular portion then disappears, apparently by dissolution, 

 which, leaving the constricted base open, thus forms the micro- 

 pyle (fig. 1, Z>). Meanwhile the gonimic contents separate them- 

 selves from the protoplasmic sac, and assuming a spherical figure, 

 sink towards the lower part of the spore-cell, by which a vacuity 

 is left in the upper part, for the reception of the spermatozoids 

 previous to impregnation (fig. 5). 



Synchronous with these changes iu the spore-cell are similar 



* Ann. des Sc. nat. iii. pi. 15. fig. 26. Bot. 1855. 

 t Ann. des Sc. nat. 1856, loc.cit. 



