336 Fresh-water Algae of Canada. 



reality. We find, however, in, " Gray's Structural and Systematic 

 Botany," fifth edition, that Pringsheim, of Berlin, is alleged to 

 have discovered the fecundation, and verified Vaucher's conjecture. 

 In the " Proceedings of the Royal Academy of Sciences, Berlin, 

 March, 1855," he states that the horn -shaped projections are 

 antheridia, or analogous of the anther. They produce myriads of 

 very minute corpuscles of oblong shape,and furnished with a bristle 

 or cilia at each end, by the vibration of which they move freely 

 in the water. These he calls spermatozoids from their resemblance 

 to the spermatozoa? of animals, and regards them as analogues of 

 pollen. At the proper time, he says, the antheridia burst at the 

 summit and discharge the spermatozoids. At this time the wall 

 of the projection, which contains the spore, likewise opens and 

 numbers of the free-moving spermatozoids find their way info the 

 opening and into contact with the forming spore, and even pene- 

 trate its substance. As a consequence of this, a wall of cellulose 

 is presently formed around the mass, and connects it into a proper 

 fertilized cell or spore." Our examination of this plant has not as 

 yet verified these discoveries, and we have reason to doubt their 

 reality. In the first place, those plants which have no capsules, 

 but whose spores are formed at the extremities of the branches, 

 have no organs at all analogous to antheridia, and, unless their 

 fertilization depends upon the pollen of other species, or other 

 plants, it must arise from another cause. Again, the attach- 

 ment of one or two spermatozoids to the aggregated granules 

 of the capsules, would not be satisfactory proof that they 

 were pollen. It is well known that these vivacious corpuscles 

 attach themselves readily by their cilia to any body with which 

 they come into contact ; being shed, therefore, from the project- 

 ing horns of the capsule, it might be expected that some of them 

 would adhere to its surface, or even penetrate its walls. That the 

 cells are not fertile, or do not form cellulose until they come into 

 contact with the spermatozoids, is, we apprehend, mere conjec- 

 ture. 



We are inclined to think, from what we have seen of this plant, 

 that the spermatozoids are true spores, and themselves fertile, 

 while the cell-mass, which, after assuming a definite form, escapes 

 from the branch, is neither more nor less than a fertile bud, — an 

 instance, by no means uncommon in the Algse, of propagation by 

 fission. Thus we shall, if this be true, have two forms of reproduc- 

 tion in Vaucheria, analogous to that which is found in some of the 



