Ill 



THE JUNGRRMANNIALRS 



85 



Elatereae 



Aneiira and Metagcria represent the sim])lest of the typical 

 anacrogynous Jungermanniales. In the former tlie thalkis 

 is composed of absokitely similar cells, all chlor()])hyll-ljearing, 

 and in each cell one or more oil bodies, like those of the Mar- 

 chantiacCcX. In Mctzgcria (Fig. 37) the wings of the thallus 

 are but one cell thick, and there is a very definite midrib, usu- 

 ally four cells thick. The apical growth in both genera is 



Fig. 37. — Metzgeria piibescens. A, Surface view of the thallus in process of division, 

 X8o; B, growing point of a branch showing the two-sided apical cell (.r) and the 

 ventral hairs (/i). X240; C, the growing point in process ux division, x, x', the 

 apical cells of the two branches, X480. 



the same, and is effected by the grow^th of a "two-sided" 

 apical cell.^ The segmentation is very regular, especially in 

 Metzgeria (Fig. 37), where each of the segments divides first 

 into an inner and an outer cell, the former by subsequent divi- 

 sions parallel to the surface of the thallus producing the thick- 



'Leitgeb (7), vol. iv. 



