30 Mr. H. J. Carter on neiv species of ffidogonium. 



only be seen when the Alga is sporing, just as those which are 

 most valuable in plants can only be seen when they are under 

 inflorescence, which is a corresponding state. They consist in 

 the presence of annular cells situated singly or in plurality be- 

 tween the ordinary cells, but with a constancy in their fixed or 

 variable number which renders the species to which they belong 

 always recognizable. Each annular cell developes one or more 

 spermatozoids, and they may be on the same filaments as the 

 spores, or on difi"erent ones. Thus the species may be mon- 

 oecious or dioecious ; while the interesting feature pointed out by 

 Prof. Pringsheim in (Edogonium ciliatum^, shows that one spe- 

 cies at least propagates somewhat after the manner of some of 

 the Cephalopoda, that is, by detaching a male organ or spore, 

 which has to undergo a secondary development before the sper- 

 matozoids are produced. As yet, I have only met with one 

 dioecious species, which, with two other monoecious species, may 

 be described as follows : — 



(Edogonium dioicum, H. J. C, nov. sp. ? PI. III. figs. 1, 2. 



Filamentous, floating, of a greenish-yellow or yellow colour, ac- 

 cording with the age and quantity of goniinic contents. Cells 

 cylindrical, 2^ to 3^ times longer than broad; chlorophyll 

 reticulated loosely, or in dense lines, more or less beaded with 

 starch-cells ; nucleus parietal. Male filaments a little less in 

 width than the female ones ; annular cells in groups of 10- 

 20 between each 2-4 ordinary cells, with one or two larger 

 than the rest ; each annular cell bearing 2-3 spermatozoids. 

 Female filaments a little wider than the male ones ; spore- 

 cells between every 4-6 ordinary cells, sometimes with only 

 one intervening, marked in the undeveloped state by annular 

 striae at the upper end, part of which enters into the inflated 

 portion ; inflation ovato-conic, truncate, partially separating 

 or dehiscing at the margin of the strise for the protrusion of 

 the internal layer or ' protoplasmic sac,^ to form the micro- 

 pyle, which is on the prominent portion. Resting-spore sphe- 

 rical, composed of granular protoplasm charged with starch- 

 cells (?), chlorophyll, and a few oil-globules ; surrounded first 

 by a thin layer (the protoplasmic sac), and then a thick, cori- 

 aceous layerf. Width of female filament about ^^oth inch; 



* Ann. ties Sc. nat. v. p. 253. pi. 15. Bot. 1856. 



t I have already used the term ' protoplasmic sac' for the lining layer 

 of the root-cell of Chara (Annals, xix. p. 15, 1857). All cells, when fully 

 developed, have two proper coats, viz. the cell-wall and protoplasmic sac ; 

 heuce it will be observed, in fig. 7, that the resting-spore is within four 

 coats ; and if this underwent deduplication, the two smaller cells would 

 each have their proper coats, as the spermatozoids in fig. 8, b, and so on. 



