CRYPT'OGAMOUS OR PLOWERLESS PLANTS. 335 



into the opening and into contact with the forming spore, or even 

 penetrate its substance ; it being an amorphous mass, coated with 

 protoplasm only. But, as a consequence of fecundation by one or 

 more spermatozoids, a wall of cellulose is presently formed on its 

 surface, converting it into a proper specialized cell or spore.* 



660. ^dogonium is a genus of simple Algie of the Conferva tribe, 

 consisting of a row of cylindrical cells placed end to end, as in Fig. 

 639. Some of these cells, usually shorter than the rest, become 

 tumid, and, without conjugation, have their whole green contents 

 transformed into a spore resembling that of Zygnema (Fig. 635) 

 and Vaucheria (Fig. 90). The fertilization of this spore has re- 

 cently been discovered by Pringsheim.f He ascertained that other 

 cells of the same little plant produce a great number of minute 

 ovoid bodies, which be names Androspores : these escape by the 

 opening of the mother cell, moving about freely by the vibration of a 

 crown of cilia attached near the smaller end. One or more of these 

 androspores fix themselves by the smaller end upon the surface of 

 the cell in which a large ordinary spore is forming, or in the vicinity, 

 and germinate there, growing longer and narrower at the point of 

 attachment, while near the free end a cross partition forms, and some- 

 times another, making one or two small cells ; this is the true anthe- 

 ridium ; for in it a crowd of spermatozoids are formed, also endowed 

 with motivity by means of vibratile cilia. Now the top of the an- 

 theridium falls off as a lid, the spermatozoids escape ; the spore-cell 

 at this time opens at the top ; one of the spermatozoids enters the 

 opening, its pointed end foremost ; this becomes stationary upon or 

 slightly penetrates the surface of the young spore, into which its 

 contents are probably transferred, by rupture or by endosmosis, and 

 a coat of cellulose is then, but not till then, deposited upon it, com- 

 pleting its organization as a spore. This spore, as in the preceding 

 cases, in due time germinates, and grows directly into a plant like 

 the parent. .But in Bolboohsete, according to Pringsheim, and in 

 SphjEroplea, as investigated by Cohn,j: the spore in germination 

 converts its contents by successive division into a large number of 

 small, oval or oblong bodies, furnished with two long cilia on a short 



* Pringsheim, in the Proceedings of the Royal Academy of Sciences, Berlin, 

 March, 1855, and Ann. Sci. Nat. ser. 4, vol. 3, p. 363. 



t Op. supra cit. May, 1856, and Ann. Sci. Nat. ser. 4, vol. 5, p. 250. 

 J Op. supra cit. May, 1855, and Ann. Sci. Nat. 1. c. p. 186, pi. 12, 13. 



