THE PLA^T GROUPS 111 



SPOROPHYTE 



1. Mature sporophyte. Select a moss plant bearing a mature 

 sporophyte and study the relation of the gametophyte 

 and sporophyte. 



a. Cut away the gametophyte on one side so as to expose 

 the base of the sporophyte. Is the sporophyte a para- 

 site on the gametophyte ? 

 b. Parts of the sporophyte. 



(1) Study sporophytes carefully with the naked eye 



and with a hand lens. Is the enlarged part (cap- 

 sule) differentiated into parts ? Note its connection 

 with the gametophyte. Draw the sporophyte and 

 label its parts after reading the text description 

 of the sporophyte. 



(2) Operadum, peristome, and spores. With dissecting 



needles remove the operculum and expose the 

 peristome. What is its structure in the moss 

 that you are studying ? How many teeth are 

 there in the peristome ? Breathe on the peristome 

 teeth and observe quickly under low power. 

 What is the nature of the movement of the 

 teeth ? What is the function of this movement 

 in the scattering of spores ? Draw a portion of 

 the peristome as seen under low and high powers. 



(3) Spores. Remove spores from a capsule with needles 



and note their size, form, and structure. Is a 

 spore a cell ? Is it a reproductive cell ? How is 

 it adapted to dissemination and to resistance to 

 the effects of sun and drought ? How do these 

 spores differ from spores of the algae ? 



(4) Spore germination. What, do moss spores produce 



when they germinate ? See text and laboratory 



