46 



(11) Transverse and longitudinal walls are formed 

 in the external cells of the ventral portion, and 

 a wall consisting of one or two layers of cells 

 is produced. 



(12) The cells of the upper tier divide up and form 

 the neck. 



(13) The top cell of the canal chain of cells divides 

 up by longitudinal division and forms five or 

 six stigmatic cells. 



The walls of the canal cell and the ventral canal 

 cell become converted into mucilage, the swelling of 

 which forces the stigmatic cells apart and the mucil- 

 age exudes through the opened neck. 



Fertilization must take place under water. The 

 antherozoids swim by means of their cilia, are at- 

 tracted by the archegonia, get caught in the mucilage 

 and wriggle themselves down the canal of the neck 

 into the ovum. Their bladders and cilia get lost 

 during the swarming in the mucilage. One unites 

 with the nucleus of the ovum, and fertilization has 

 taken place. 



EEStJLTS OF FERTILIZATION. 



The ventral portion from this time is called the 

 Calyi^tra. 



(1) The fertilized ovum secretes a cellulose wall 

 and forms respectively the epibasal and hypo- 

 basal cells. The epibasal cell becomes the 



