CYSTOSPERMEiE. 185 



especially in respect to those most interesting species which 

 I have described as producing true sporangia, without union 

 of the filaments. 



This discovery of the identity of the mode of reproduction 

 of the two families of Confervas, hitherto treated of, leads 

 necessarily to some general, and not unimportant conclusions. 



Thus, it furnishes satisfactory evidence of the intimate 

 and general connection which exists between these tw^o 

 families, Avhich include such a considerable proportion of the 

 freshwater Confervce, whereby much light is thrown upon 

 the often canvassed and much disputed subject of the ani- 

 mality of the conjugating genera, for it proves, since in 

 reality a conjugation takes place for the formation of all 

 true sporangia, that both stand upon the same footing as 

 regards their animal natui-e, a fact, which hitherto has never 

 been suspected, the vegetable character of the Cystospermece 

 having long been considered as established, and that if those 

 species which exhibit the curious phenomenon of conjugation 

 are really animal, so are all the true Confcrvce ; thus, if these 

 should at any subsequent period be removed from the vege- 

 table kingdom to the animal, so ought, as an inevitable con- 

 sequence, all the other ConfervcB which I have included in 

 the group of Ci/stospermece. 



But it appears to me that, from the fact disclosed of the 

 union and concentration of the contents of tico cells in so many 

 Confervce, no argument can be deduced either in favour of 

 the sexuality or animality of the ConfervcE, numerous species 

 occurring, as already observed in the Introduction, in which 

 this curious phenomenon is wdiolly wanting. 



For my own part, I trouble myself but little with the 

 disputes about the boundaries of the two great divisions of 

 the organised world, which forcibly remind me of the search 

 carried on by ancient philosophers, for days and years, after 

 the much-desired, but imaginary philosopher's stone, endow^ed 

 with such all-pervading influence, or the equally fruitless in- 

 quiry after perpetual motion, or any other of the wild chimeras 

 to which the minds of men have from time to time been 

 given. It is my belief, that no such rigid boundary exists ; 



