THE "pro-embryo" OF CHARA. 361 



the oopliore, the sporophore being represented by the embryo, i.e., 

 the product of the develoiDment of the central- cell of the archego- 

 nium. In order to indicate the fact that no spores are ever pro- 

 duced, so far as is at present known, by the sporophore of Chara, 

 we may speak of this ^Dlant as being " aiDosporous," using a word 

 which is symmetrical with the term ** apogamous," apiDlied by De 

 Bary to those Ferns in whose life-history no process of sexual 

 reproduction occurs. 



If this interpretation of the facts in the life -history of Chara be 

 in any measure a correct one, it will necessarily have an important 

 bearing upon the question of the systematic j)osition of the 

 CharacecB. This question has been recently discussed in these 

 pages by Bennett'" and by Caruel.f The former, accepting the 

 prevailing account of the hfe-history of Chara, and perceiving the 

 many features which the Characem and the 2IuscinecB possess in 

 common, suggests that the Characem may be Mosses, rendered 

 abnormal by their aquatic habit, in which the formation of the 

 non-sexual genere^tion (sporophore) is altogether suj)iDressed. 

 There is nothing in the views advanced in this paper to contradict 

 the existence of a relationship between the Characem and the 

 Muscinea ; on the contrary, there is much to estabhsh it. It is 

 true that the "pro-embryo" of Chara cannot any longer be 

 regarded as the homologue of the protonema of a Moss, but, on the 

 other hand, it is here contended that the embryo is the homologue 

 of the sporogonium of a Moss ; so that although these views 

 destroy one link in the chain of analogies and homologies which 

 connects the Characece and the MuscinecB, they replace it by a 

 stronger one. I quite agree with Bennett's conclusion, on account 

 of the facts detailed in the earher part of this paper, that it is 

 incorrect to place the Charace(B among the CarposporecB, for they 

 have stronger affinities with the Mosses. 



Still it must not be overlooked that the Characece do possess 

 certain featui-es in common with some of the CarposporecB. such as 

 a very simple histological composition and their peculiar cortica- 

 tion. And further, although, as Bennett states and as I have 

 ah'eady pointed out, the " nucule " of Chara is essentially different 

 from a carjpogonium, — is, in fact, an archegonium, — yet it presents a 

 peculiarity in which it resembles the carpogonium of certain Car- 

 posporecB, and in which it differs from the archegonium of a Moss. 

 This peculiarity consists in the existence of one or more cells 

 (Wendungszellen, A. Braiin) at the base of the central-cell, which 

 have been divided fi-om it. These cells are usually regarded as 

 being the representatives of those forming the trichopore of the 

 FloridecB, that is, as the rudiments of an organ which exists fully 

 developed in allied plants, the antherozoids of which are not 

 endowed with the power of movement, but which is unnecessary in 

 the CharacecB, because in them the antherozoids are actively motile. 



* « Journ. of Botany.' New Series. Vol. vii,, July, 1878, p. 202. 



\Idem. New Series, Vol. vii., September, 1878, p. 258. Also 'La Mor- 

 fologia Vegetale.' Pisa. 1878. 



8a 



