Vol. IV. APRII., 1895. No. 4. 



ADVENTITIOUS BRANCHING IN I.IVKRWORTS. 



BY DAVID M*ARDI,K. 

 (Read before the Dublin Naturalists' Field Club, March 12th, 1895). 



Vkgktativk propagation amongst Hepatics is well demon- 

 strated by some of the species which are of frequent occurrence 

 in Ireland, and good examples are to be seen in plants of both 

 frondose and foliose groups. Marchayitia and Luyiularia have 

 special receptacles on the upper side of the frond or thallus 

 called gemmae- cups, from the floor of which cellular papillae 

 arise, which grow into flat or spherical stalked bodies, the 

 gemmae. In Lunularia the rim of the cup is partial or 

 crescentic. In Marchantia, on the contrary, it is complete. 

 The escape of the gemmae is facilitated by club-shaped hairs 

 which grow between them. The cell-walls of these hairs are 

 mucilaginous, swell up and force the gemmae out of the 

 receptacle, when, under favourable circumstances, each one is 

 capable of producing a perfect plant. 



In the genus Blasia these receptacles are flask-shaped ; the 

 gemmae, floating in a transparent mucilaginous substance, are 

 often found at this early stage furnished with a single root-hair 

 before emerging from their mucous receptacle. 



The smallest portion of the frond oi Marchantia or Ltcmdaria 

 broken off and placed in a favourable position, will grow. I 

 have divided a number of plants of "the rare Codojiia Ralfsii, 

 Gott (frequently cultivated at Glasnevin) bypassing the sharp 

 blade of a knife through them as they grew ; after a few days 

 I gently moved these parts a little distance and added soil 

 between them, watered and covered the pot in which they 

 were growing with a bell-glass, and in no instance did they 

 show any bad effects from this treatment, but grew on rapidly 

 and bore fruit. 



In the genus Metsgeria adventitious shoots frequently grow 

 from the margin and other parts of the frond, notably in 



A 



