The Position of Hepatics and Mosses 



employ the origin and position of antheridia and archegonia as a 

 criterion, then the vegetative part of hepatic plants and moss 

 plants is an homologous stage with a fern prothallium. 



,ProtH*lllu,>n.. 



The sexual or first generation. 

 Under side of a mature fern-pro- 

 thallium on which are borne an- 

 theridia male organs, and arche- 

 gonia female organs. 



A young fern prothallium. 



Again, if one employ as a criterion that which originates 

 from a fertilised archegonium, then the spore-case, foot, and 

 pedicel (sporophyte) of an hepatic and moss are homologous 



.Wall-cell. 



Sperm cells coiled in little 

 vesicles in an antheridium. 



..Sperm- tell. 



Sperm-cells escaping from an antheridium. 

 Vertical sections of Antheridia. 



with the spore-cases, fronds, stems, and roots of a "fern-plant" 

 (sporophyte). The sporophyte is known as the asexual gen- 

 eration. 



67 



