ACROGENSVv ' I IQ 



embryo of Chara, from each of which an independent 

 plant may arise. 



The urn, or capsule, is not the real fructification of a 

 moss, but its product, since Mosses, like Liverworts, etc., 

 possess both antheridia and pistillidia, although they are 

 often inconspicuous. They are found either together, 

 or on different parts of the same plant, or on different 

 plants. They are usually situated at the bases of the 

 leaves, close to the axis. The antheridia are globular 

 or elongated capsules containing sperm-cells, each of 

 which produces a moving antherozoid, which escapes at 

 the summit of the capsule. Hair-like filaments (para- 

 physes) around the antheridia are considered to be ster- 

 ile or undeveloped antheridia. The archegonia are like 

 those of the Hepaticeae, and when fertilized the embryo- 

 cell develops by cell-division into a conical body ele- 

 vated upon a stalk. This tears the walls of the flask- 

 shaped archegonium by a circular fissure, carrying the 

 upper part as the calyptra, or hood of the " urn," while 

 the lower part remains as a sort of collar around the 

 stalk. 



6. The characteristics of the type of Acrogens are the 

 growth of cells at the summit only ; the appearance of a 

 distinct cortical portion, or epiderm, and of vascular and 

 fibrous tissue ; and a sort of alternation of generations in 

 the provision of a prothallus, so that plants of this type 

 may not improperly be designated Prothallus plants, as 

 the higher types are sometimes known as Monocotyled- 

 onous, or Dicotyledonous plants. 



7. As an illustration of the reflections natural to a 

 well-regulated mind from the study of natural objects, 



