144 



Practical Plant Biology. 



In this way the stem, the leaves and even the archegonium of the 

 gametophyte may, by the production of rhizoids, originate new 

 plants. The sporophyte has the same power, and plants may be 

 derived in like manner from parts of the theca and seta. 



An interesting observation has been made on this method of 

 reproduction in Funaria. If leaves from around the antheridia on 

 the male shoot are taken off and induced to give rise to new 

 plants, it is found that these plants can only produce male shoots 

 bearing antheridia. Whereas plants similarly developed from 

 leaves of the female shoot, and even from the archegonium 

 itself, produce the normal bisexual plants with male and female 



FUNARIA 



Sporophyte 



Foot, seta, theca. 



Semi-Parasite 



Spore 



Antheridium Archegonium 

 Male Shoot Female Shoot 



Gametophyte 



IProtonema, leafy plantJ 

 / Holophytic. _/ 



FIG. 31. Diagram summarising the life-history of Funaria. 



shoots. Apparently just before the bifurcation of the stem takes 

 place, a cell division occurs in which the two cells arising receive 

 different potentialities from the parent cell. In this way we may 

 suppose that either a substance is omitted from one that is neces- 

 sary for the formation of archegonia or something is included 

 which inhibits their development. 



PRACTICAL WORK. 



Examine portion of a patch of Funaria and notice how closely the sexual 

 shoots grow together. 



Remove a small group of plants by breaking the sod carefully. Wash 



