1885.] 



MICROSCOPICAL JOURNAL. 



advanced the theory that the ciliated 

 gonidium of Vauchcria is in reality 

 a densely crowded aggregation of bi- 

 ciliated zoospores, similar to those 

 found in many other Confervoid AlgcE. 

 Although this has by no means been 

 proven, yet I cannot help calling the 

 attention of the members of this so- 

 ciety to a fact which I think strongly 

 bears out the said theory : While 

 watching a gathering of Vaiicheria 

 one morning when the plant was in 

 the gonidia-forming condition (which 

 is usually assumed a few hours after 

 daybreak) I observed one filament, 

 near the end of which a septum had 

 formed precisely as in the case of or- 

 dinary filaments about to develop a 

 spore. But, instead of the terminal 

 cell being filled with the usual densely 

 crowded cluster of dark green gran- 

 ules constituting the rapidh' forming 

 spore, it contained hundreds of ac- 

 tively moving nearly transparent zoo- 

 spores and nothing else. Not a single 

 chlorophyll granule was to be seen. 

 It is also to be noted, as a significant 

 fact, that the cellulose wall was intact 

 at the apex, instead of showing the 

 opening through which in ordinary 

 cases the gonidium escapes. It would 

 seem to be a reasonable inference, I 

 think, based upon the theory above 

 stated, that in this case the newly 

 formed gonidium, unable to escape 

 from its prison by reason of the ab- 

 normal strength of the cell wall, be- 

 came after a while resolved into its 

 component zoospores. 



I very much regret that my descrip- 

 tive powers are not equal to convey- 

 ing a suflScient idea of the intensely 

 absorbing interest possessed by this 

 wonderful process of spore formation. 

 I shall never forget the bright sunny 

 morning when for the first time I wit- 

 nessed the entire process under the ' 

 microscope and for over four hours 

 scarcely moved my eyes from the tube. 

 To a thoughtful observer I doubt if 

 there is anything in the whole range 

 of microscopy to exceed this phenom- 

 enon in point of startling interest. 

 No wonder that its first observer pub- 



lished his researches under the cap- 

 tion of ' The Plant at the Moment of 

 Becoming an Animal.' 



The process of spore formation just 

 described, it will be seen, is entirely 

 non-sexual, being simply a vegetative 

 process, analogous to the budding of 

 higher plants, and the fission of some 

 of the lower plants and animals. / 'aji- 

 cheria has, however, a second and far 

 higher mode of reproduction, viz : by 

 means of fertilized cells, the true oo- 

 spores, which lying dormant as resting 

 spores during the winter are endowed 

 with new life by the rejuvenating in- 

 fluences of spring. Their formation 

 may be briefly described as follows : 

 When }^aucheri'a has reached the 

 proper stage in its life cycle, slight 

 swellings appear here and there on 

 the sides of the filament. Each of 

 these slowly develops into a shape 

 resembling a strongly curved horn. 



Fig 5. — Vaucheria sessilis. 



This becomes the organ termed the 

 antheridium, from its analogy in 



t'iG. 6. — Vaucheria geminata. 



function to the anther of flowering 

 plants. While this is in process of 

 growth, peculiar oval capsules or 

 sporangia (usually 2-5 in number) 



