i6g 



SOME POINTS 

 IN THE BIOLOGY OF HEPATIC^E. 



F. CAVERS, B.Sc, 



)'orkshirf Collegi', Leeds. 



If one may judge from the number of additions wliich have been 

 made to the literature o'i the Hepaticae during- the last few years, 

 it would appear that the study of this group of plants is grow- 

 ing- in favour with botanists in this country, who now have 

 in Mr. W. H. Pearson's 'Hepaticae oi the British Isles' a 

 splendidly-illustrated work o'i reference, besides the handv and 

 inexpensive 'Key to the British Hepatica;,' by Mr. Macvicar, 

 and the useful 'List of the British Hepaticce,' by Mr. Lett.* 

 The object of the present paper is to set forth briefly some of 

 the outstand- 

 ing- facts in 

 the biology of 

 the Hepatic^, 

 leaving out 

 of account 

 the organs 

 concerned in 

 the propaga- 

 tion of the 

 species and 

 dealing solely 

 with the vege- 

 tative organs, 

 with special 

 reference to 

 the \' a r i o u s 



ways in which these are modified and adapted to the special 

 needs of the plant. 



Most people who are interested in plant-life are familiar with 

 the ribbon-like or thalloid shoots of Marchantia polymorpha and 

 Lunularia cruciata, which are so often seen covering the soil in 

 greenhouses, the green branched thallus usually bearing on its 

 upper surface the characteristic circular {Marchantia) or crescent- 

 shaped {Lunularia) cups, which contain numerous small brood- 

 bodies, or gemmae. The surface of the thallus is divided up into 

 polygonal areas, each area having in its centre a small light 



* Lett, H. W., a list, with descriptive notes, of all the species of hepatics 

 hitherto found in the British Islands. Eastbourne, 1902. 



i9o_^ May i. 



Fig. I. — Fegatella conlca. Growing- point from .ibove, showing 

 the roflcxcd scales and the areolatioii of the thallus. X 10. 



