206 PRACTICAL BOTANY 



truncated pyramid may be recognized in a central position : 

 this is one of the initial cells. 



VII. Cut successive transverse sections of the apex, so as to 

 pass immediately below the base of the depression : one of 

 these sections will include the initial group, which will then 

 appear to be composed of some four or five cells, of oblong 

 form, placed in a row, side by side. 



VIII. Cut transverse sections through the fertile branches of 

 the thallus, so as to traverse the mature conceptacles : mount 

 in glycerine, and examine under a low power. First take 

 sections of the male thallus, and having found a point where a 

 male conceptacle has been cut in median section (i.e. so as to 

 traverse the ostiole) note 



1. The spherical or flask-shaped cavity. 



2. The ostiole, by which the cavity communicates with the 

 exterior. 



3. The hairs, which almost fill the cavity, and may even 

 protrude through the ostiole. 



4. The antheridia, which are single oval cells, borne often in 

 large numbers on these hairs. 



It may further be noted that the cavity is lined by a small- 

 celled tissue, from which these hairs arise, and that this 

 graduates imperceptibly into the other tissues of the thallus, 

 which are similar to those of the vegetative parts. 



IX. Tease out with needles the contents of a male con- 

 ceptacle in glycerine, mount, and observe under high power : 

 note 



1. The thin, colourless, branched hairs, which bear the oval 

 cells (antheridia) with their yellowish granular contents. 



2. The mode of branching of the hairs which bear the 

 antheridia. 



3. Long hairs, branching less frequently, or not at all : these 

 do not bear antheridia. 



X. With the above compare sections cut through female 

 conceptacles, mounting as before : in its form, and also in its 

 relation to the tissues surrounding it the female conceptacle is 

 similar to the male ; the difference is in the contents, which 

 may be seen to consist of 



