(41) 



II. BRYOPHYTES. 



The abnormalities occurring in Mosses and Liver- 

 worts will be considered together. 



As is to be expected in such a lowly group as the 

 Bryophytes, affording by their simple organization 

 such a restricted field for the occurrence of deviations 

 from the normal structure, the number of different 

 kinds of abnormalities is very limited, and only a 

 small section of this work will be devoted thereto. 



1. THE SEXUAL GENERATION. 



Vegetative Organs. — Shoot. — Dichotomous branch- 

 ing of the stem is very rare in Bryophytes. Hagen 

 figures a remarkable case of multiple forking of the 

 male plant in the moss Schistostega, so that the 

 appearance is afforded of a single stem bearing a 

 number of stalked male flowers (PI. Ill, fig. 1). 



Abnormal branching of the stem was observed by 

 Debat in the moss Aulacomnium palustre ; as a result 

 of pressure of snow, or other cause, the stem grew 

 horizontally instead of vertically, and did not complete 

 its normal development. Lateral, slender branches 

 were given off which grew vertically upwards, and 

 had the general appearance of stolons, bearing leaves 

 of a different shape from the normal. The stem of 

 the liverworts belonging to the Jungermanniege group 

 is full of resting, growing points ; if, as Schosta- 

 kowitsch found, the stem be wounded in any part, 

 these at once grow out into leafy shoots, affording an 

 interesting case of abnormal proliferation. It was 

 owing to this character that that investigator could 



