— 41 - 



infered that the lack of rhizoid production in these cultures 

 was due to the medium of growth, either upon flower pot 

 pieces or in water. Cultures which from the beginning were 

 made upon earth showed essentially the same manner of 

 growth, except that the side branches were robust instead 

 of slender, of equal diameter instad of tapering and were 

 distinctly positive heliotropic. It was only very rarely that 

 a protonema branch was found penetrating the soil and 

 becoming of a rhizoid nature. The same result was obtained 

 with protonema which were grown either in water or upon 

 flower pot pieces and then placed upon the soil, the further 

 growth still being without rhizoid development. Luxuriantly 

 growing protonema from the stem of Fuuaria were half 

 covered with earth without any appearance of rhizoids. 

 Schimper l grew Funaria protonema from the spores which 

 did not show any rhizoid production. 



SUM31ARY. 



Considering the various species of moss plants used in 

 the forgoeing experiments, there are, notwithstanding the 

 variety of results, many striking similarities in the manner 

 of regeneration , a brief summary of which will be brought 

 together in the following conclusions : 



1. The majority of moss leaves used showed a remark- 

 able power of regeneration, producing either rhizoids or pro- 

 tonema, with the later appearance of new leafy shoots. 

 The rhizoid or protonema production was carried out in 

 both light and darkness. 



2. The point of origin of the new growth from the 

 leaf in some cases depended upon contact and illumination 

 and was independent of gravity (Mnium). In other cases the 

 protonema had a definite origin which was independent of 

 external factors , and depended solely on the leaf structure: 

 from the ventral side of the leaf as in Atrichum, Poly- 



Rech. anat. et morph. sur les mousses, Plate I. 1848. 



