SELAGINELLA GAMETOPHYTE 155 



THE GAMETOPHYTE OR OOPHYTE 



VI. Spores of both kinds may be obtained free by drying 

 branches which bear sporangia on sheets of paper. Pick out 

 the macrospores, and mount them in olive-oil : dissect off the 

 brittle outer coat of the spore with needles, and examine under 

 a high power. It will be seen that the chief contents of the 

 ripe spore are a protoplasmic matrix inclosing oil-globules and 

 aleurone-grains, while traces of the cells of the prothallium may 

 be recognized even in these preparations. 



If plenty of spores are to be had, embed a quantity of them, 

 and to cut sections, mounting them in glycerine. Observe 



1. The character of the wall, consisting of 



a. An outer thick, yellow exospore. 



b. An inner thin endospore. 



2. The contents as above described : the natural position 

 of the cellular tissue of the prothallium may be seen to be at 

 the apex of the cavity of the spore. 



VII. Spores of both kinds should be collected in considerable 

 quantity by drying on paper, and then be sown on moist soil 

 or sand, and left to germinate. In a few weeks young seedlings 

 will be seen with an erect axis, bearing small leaves. Note 

 that the axis of the seedling branches at an early period. 



Remove some of these seedlings from the soil, and note the 

 monopodial branching of the root, and the macrospore still 

 attached laterally to the axis. 



Longitudinal sections should be made through the young 

 seedling, so as to traverse also the macrospore attached to it : 

 in such sections it will be readily seen that a lateral outgrowth 

 (the foot) projects from the base of the axis into the cavity of 

 the macrospore : also that the latter is filled with a cellular 

 tissue of the prothallus, from which the nutritive substances 

 above noted in the mature macrospore will have been re- 

 moved. 



A detailed description of work to be done on Lycopodium 

 davatum, as a homosporous Lycopod, is given in the larger 

 edition. 



