lO CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 



borne on a short stalk. The sac is bounded on the outside by 

 a wall composed of a single layer of sterile cells, and the 

 whole interior is occupied by a compact mass of fertile cells, 

 each one of which gives rise to a single male cell, or sperm. 

 When the antheridium is mature, it absorbs water and bursts 

 its wall, allowing the sperms to escape and swim away. Each 

 sperm consists of a slender body, and swims by means of two 

 long and delicate cilia attached at one end. 



The archegonium may also be stalkless or borne on a short 

 stalk, but is more slender than the antheridium. The single 

 female cell, or egg, is developed in the swollen basal portion 

 which is called the venter, and this is tipped with a somewhat 

 longer cylindrical portion called the neck. Both venter ahd 

 neck are bounded on the outside by a wall composed of 

 sterile cells. The egg represents the lowest of a row of cells 

 enclosed by this wall, the remaining cells, which fill the neck 

 and a portion of the venter as well, being known as canal cells. 

 When the mature archegonium absorbs water, the neck opens 

 at the tip, and the canal cells break down into a mass of 

 slime, some of which escapes through the opening. In this 

 way a free canal is formed which leads from the outside into 

 the venter, and at the base of this canal the egg becomes 

 rounded off. The sperms, attracted by the protoplasmic slime 

 exuding from the archegonium, swim toward it, and one of 

 them makes its way down the canal, uniting with the egg 

 and thus completing the process of fertilization. 



As soon as this has been accomplished, the fertilized egg, 

 without escaping from the archegonium, begins at once to 

 develop into the sporophyte, which remains in contact with 

 the gametophyte during its entire life, without being organ- 

 ically connected with it. The chief function of the sporophyte 

 is to develop asexual spores, but some of its cells invariably 

 remain sterile and perform functions not connected with 

 reproduction. In the more primitive Bryophytes it is practi- 

 cally destitute of chlorophyll, and is therefore wholly dependent 

 upon the gametophyte for food, living as a parasite upon it. 

 In the higher forms it develops green cells, capable of per- 

 forming photosynthesis, and probably derives nothing from the 

 gametophyte except solutions of inorganic substances. In 

 such cases the parasitism is only partial. The portion of the 



