A dven titious Branching in L iverworts. 83. 



lyast year I collected Lejeunea serpyllifolia in Mr. Hickson's 

 wood at lyispoll near Auniscaul, Co. Kerry, and when exaniin- 

 ingthe plant on the table of a dissecting microscope, I was struck 

 with the unusual and abnormal branching of one of the 

 specimens, and I proceeded to ascertain the cause of it. From 

 copious material, I found that these shoots or branchlets came 

 from all sides of the stem and elsewhere. Figure 3 represents 

 a portion of the stem and attached leaf-lobule, with young 

 shoots arising from each. The leaves of the plant exhibited 

 still more remarkable examples of adventitious shoots. Figure 

 4 shows the first stage of growth. It is from a portion of a 

 leaf-margin highly magnified, and shows these shoots to be 

 outgrowths of a simple cell. I noticed that the cells in these 

 proliferous plants were more than usually chlorophylliferous. 

 Figure 5 shows a further stage of development. Figure 6 

 shows a leaf of Lejeunea serpyllifolia with six adventitious 

 shoots, in some of which the leaves are well marked. Figure 

 7 shows further development of a leaf-shoot with three leaves 

 and two perfectly formed stipules, and, at the base of the stem 

 a couple of root-hairs. The contents of the cells in the old leaf 

 have disappeared, the walls near the attachment of the plantlet 

 are beginning to disintegrate, and very shortly it would become 

 independent from the mother-plant. 



The delegation of rooting apparatus called the flagellae to 

 leafy branchlets, which occurs in some liverworts, is 

 remarkable. These flagellae enable the plants to fix them- 

 selves firmly where they grow, and assist them to resist 

 drought or to start off on a separate existence and continue 

 the life of the parent plant. That the reproduction of the 

 species of Lejeimea by adventitious shoots is an unusual 

 occurrence amongst those which grow in Ireland, there 

 can be no doubt. I have examined .many specimens from all 

 parts of the country during a number of 3^ears, and have not pre- 

 viously found the vegetative budding in Lejeunea as now 

 described. 



This mode of reproduction is important in a marked degree, 

 as occurring in a genus of which we have tropical and sub- 

 tropical species growing in Ireland, and is favourable to the 

 views held by my late excellent friend, Dr. Spruce, in his 

 treatise on an Irish Lejetmea^ : — " No existing agency is 



1 "On Lejeunea Holtii from Killarney." jottrnal of Bot., vol. xxv., 1887 

 p. 72. 



A 2 



