32i 



PLANT STUDIES 



At the bottom of the coiisi)ieiioiis notch in the pi'othal- 

 linni is the growing i^oint, representing tlie upex of the 

 phmt. This notch is always a conspicnons feature. 



Tlie a.ntlieridia and archegonia are usually developed on 

 the under surface of tlie prothallium (Kig. 303, A), and dif- 

 fer from those of all Bryo})hytes, except the Anflioreros 

 forms, in Ijcing sunk in the tissue of the prothallium and 

 opening on the sui-face, more or less of the neck of the 

 archegonium pi'oji'cting (Fig. '.'04:). The eggs are not dif- 

 ferent from those formed within the archegonia of 15i'3'0- 



Fi.;, 2;i.-,. AiitlM'.-Hliuiii nf /■/.,)., iZJi, sh.Mvin- «all rrlls („i, nprnin^- f,,r PSPII],,. of 

 •^l"'l'l" ""'llHT rclls I, 1, .■sc;i|i,>a lIHilhcr itIIs In. S|,rn,is frrc from ulotlliT rclls 

 I/O, .shoMiiii,' f^piral ;oi<l iiiulticiliatu chiirarliT. — CALinvni,!,. 



phytes, hut the sperms arc very dilTcreut. The I'.ryoiiliyte 

 sperm has a small l)ody and two long cilia,, while the I'teri- 

 dophyte sperm has a long s])ira.lly coiled Ix.dy, l)lunt behind 

 and ta])criug to m. jiiiint in front, wher<> numerous cilia, are 

 dcvclc|)cil (Fig. -^iil.^). It is, tlicrcforc, a huge, s])irally ceiled, 

 muUiciliate s])crni, and is (piitc chara<'tci-ist ic (if all I'tcrido- 

 phytos excei)ting tlic Chib-mcsses. 



When the iir(>l,h:i,llia, arc developing the aidheriilia liegin 



