3«4 



VASCULAR CRYPTOGAMS. 



The development of the Anther ozoids is preceded, in the genus Salvinia, by the 

 formation of a very rudimentary male prothallium. The microspores lie imbedded 

 in a mass of granular hardened mucilage, which fills up the whole of the microspo- 

 rangium ; they do not escape, but each of them emits from its endospore a tube 

 which pierces the mucilage and the wall of the sporangium and forms a septum at 

 its curved end (Fig. 285, A and B). The terminal cell of the tube thus produced 

 is again divided by an oblique wall, after which the protoplasm contracts in the tw^o 

 cells (which Pringsheim together calls the antheridium), and splits up by repeated 

 bipartition into four roundish primordial cells, each of which forms an antherozoid. 



Fig. 285.— 5a/2//«?Vi! nutans; A an entire microspo- 

 rangium, the tubes of the microspores st breaking through 

 (X about 100) ; K one of these tubes st protrudnig from tlie 

 envelope of the microsporangium h (x about 200), a the 

 antheridium still closed; C tube with the empty anthe- 

 ridium ; D antherozoids (XSoo) (after Pringsheim). 



11;^ IW-^ 



Fig. ■2^6.—Marsi/en sal-vatrix; A macrospore sp with its mucilaginous envelope j/and the apical papilla projecting into its 

 funnel : in the papilla is a broad yellowish drop, sg the ruptured wall of the macrosporangium ( X about 30). B a microspore 

 burst after the escape of the antherozoids ; ex the exospore, dl the protruding endospore containing granules, z, z the spiral 

 antherozoids, y, y their vesicles containing starch-grains. The mucilaginous envelope of the microspore is no longer in 

 existence (X 550). (The exospore does not show the regular arrangement of the protuberances, which is indicated erroneously 

 in the figure.) 



In addition a small portion of the contents remains inactive in each of the two 

 cells. The antheridial cells burst by transverse slits to allow the escape of the 

 antherozoids. The spirally curved body of the antherozoid lies in (?) a vesicle, 

 which, according to Pringsheim, it does not leave even during the ' swarming.' In 

 Marsilea and Pilularia the antherozoids are produced in the interior of the micro- 

 spores themselves ; their protoplasmic contents contract into a longish round lump 

 placed eccentrically, which separates into eight primordial cells by three successive 



