STRUCTURE.] FLOWERLESS PLANTS. 83 



Brit tie worts (Diatomseceae), or simple cells, as in some of the 

 genera constituting Blights among Coniomycetous Fungals. 

 And even in these instances where flowering and flowerless 

 plants resemble each other, the similarity is confined to the 

 organs of vegetation, no resemblance being usually discover- 

 able, except by the aid of forced analogy, between the repro- 

 ductive organs of the two great forms of plants. It would 

 seem, indeed, as if the mode of producing reproductive organs 

 was wholly changed among flowerless plants, and that such 

 resemblances as sometimes appear to remain, are but the 

 result of general tendencies which, perhaps, are never lost in 

 any part of the kingdom of plants. It is, therefore, mainly to 

 the peculiarity of the reproductive organs that the following 

 remarks will have relation. 



There are two main questions which require to be con- 

 sidered independently of the special circumstances that vary 

 from one natural order to another. They are : 1 . Have 

 flowerless plants sexes? 2. Have they seeds ? 



The question of SEXES has long divided the botanical 

 world. There are some who, like Linna3us, assume sexuality 

 to be indispensable, and who therefore find traces of it every 

 where. There are others who, perceiving no necessity of the 

 kind, demand proof of the so called sexes being so, and refuse 

 to acknowledge sexes in the absence of the same proof as is 

 required among flowering plants. The first are sometimes 

 satisfied with assuming the existence of a male and female 

 principle even in the cells of Confervse, where nothing visible 

 exists ; the second are of opinion, that what can neither be 

 seen, nor detected otherwise, cannot be said to have existence. 

 The former opinion is maintained, with his usual acuteness, 

 by Mr. Thwaites, as will be seen hereafter under Mosses and 

 Brittleworts. And the point may be conceded in the view 

 which he takes of sexuality : for it is not so much the mere 

 presence of sexes, or of a mysterious sexual essence, that is 

 denied, as that the organs called sexual in flowerless plants, 

 are of the same, or a similar, nature as those known to be 

 sexes in the higher orders. 



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