73 



arises from one cell of the protliallium. The wall is 

 one cell tldck, and encloses a few mother cells. Each 

 mother cell produces one antherozoid thus : 



1 . The nucleus grows large and corkscrew-like, 

 and is invested ])j sl specialised part of the 

 protoplasm (kinoplasm) which is very clear at 

 the anterior end. 



2. The cilia are produced from the peripheral 

 protoplasm and become attached to the an- 

 terior end. 



8. A vesicle remains attached to its posterior end, 

 which probably has its origin in the central 

 vacuole of the mother cell. 



The dome-shaped end of the antlieridium becomes 

 disorganised, and so do the antherozoid mother cells, 

 and the antherozoid s swim out. 



Archegonia. Each archegonium arises from a 

 superficial cell, and projects considerably beyond the 

 surface. It presents the appearance of a water- 

 bottle, the swollen part of which is embedded in the 

 tissue of the prothallium. The swollen part called 

 the ventral portion encloses the ovum, which is also 

 known as the oosphere. This ovum consists of a large 

 nucleus surrounded by a mass of dense protoplasm. 

 Above the ovum, approaching the neck of the bottle- 

 shaped structure, is a small cell called the ventral 

 canal cell. The neck portion consists of four rows of 

 neck cells, which surround one long cell known as 



