46 



PRINCIPLES OP PLANT-TERATOLOGY. 



rations of gemmae at the apex of the leaves of the 

 moss Orihotrichum phyllanthum; he also observed them 

 on the leaves of the mosses Grimmia, Syrrhopodon, 

 and Galymperes ; in the last-named only the lower part 

 of the leaf developed its parenchymatous tissue in the 

 ordinary way, all the rest being used up for gemmae- 

 production. They also occur at the apex of the leaf 

 of the liverwort Diplopliyllum albicans. All these cases 

 are, however, normal for the genera or species con- 

 cerned ; yet they can only represent abnormalities 

 which happen to have become fixed. 



Finally, there are the fairly numerous cases of 

 adventitious shoots occurring on the " inflorescence." 



Klein, for instance, describes how, in the liverwort 

 Marchantia pulymorpha, thallus-shoots grew from the 

 "root-furrows" of the stalks of antheridio- and arche- 

 goniophores when these were bent down on to the soil ; 

 they also occurred on the upright ones, but, in these, 

 were very small and not externally visible. He states 

 that these occur normally as resting-buds. 



Bolleter induced shoots to grow from the lower side 

 of the " cap " of both antheridio- and archegoniophore 

 in Fegatella conica. None could be obtained from the 

 stalk, the reason of this being that in this plant the 

 stalk is a more ephemeral structure than it is in 

 Marchantia. 



Vochtino* laid the cut-off stalks of the archegonio- 

 phores of Marchantia polymorpha and Lunularia, either 

 entire or in pieces, on moist sand, when in all cases one 

 or two adventitious shoots appeared at the basal end, 

 either on the cut edge or near it. When the " caps " 

 were cut off their stalks and laid on sand, shoots were 

 formed from furrows close to the cut surface on the 

 lower side (PL IV, fig. '3b and c). If the "rays" 

 were isolated, shoots always arose on them at their 

 basal end. All his experiments were made with in- 

 florescences containing unfertilized archegonia. 



Kreh caused shoots to develop from the base of old 

 fertilized archegonia- walls in the liverwort Aplozia. 



