REPRODUCTION. 



191 



processes of conjugation in Spirogyra longata ; the upper portion 

 of the figure shows two segments, the cell-walls of which begin to 

 form projections at a ; at b projections are in contact. Further 

 progress is shown at A ; at B the final stages are shown. Such 

 conjugating cells are called " gametes." " Zoogametes " is the 



B 



FIG. 114. Various stages of the antberidial devel- 

 opment of Adiantum capillus (I, II, III), 

 p, Prothalliutn ; a, antheridium ; s, spermatozoid with at- 

 tached remnant of the mother-cell (6). (After Sachs.) 



FIG. 113. Funnria liygro- 

 tnetrica. 



A, Archegonia (a) on the apex of 

 the stem between the leaves (6) ; 

 B, magnified archegonium (in 

 glycerin) ; 6, ventral portion 

 with oosphere ; h, neck of ar- 

 chegonium ; w, mouih of arche- FIG. 115. Longitudinal section of the archego- 

 faf'ter" 1 ' fertilization ) P ^( Af te? nium of Adiantum capMu*, before fertilization. 

 Sachs.) h, Neck ; s, ventral canal-cell ; e, oosphere, (After Sachs.) 



term applied to conjugating swarm-spores. Fertilization among 

 Vaucheria differs very distinctly from that among Spirogyra ; in 

 the former the oogonium og (Fig. Ill) is quite different from the 

 antheridium #; osp in E is the oospore containing fat- or oil- 

 globules. 



