MetapJiyta Liliu-iii. 143 



where AST stands for asexual generation, and S T for sexual 

 thallus. 



SECTION III. MONOCOTYLEDONES LILIUM. 



We now reach that point in our examination of the mor- 

 phology of plants when it is necessary to consider what are 

 popularly known as the flowering plants. For that purpose 

 we shall devote our attention to two forms which illus- 

 trate well the characters of that group. A thorough grasp 

 of the preceding section, where we examined Selaginella in 

 detail, will help us considerably towards understanding the 

 at first sight very different organisation of the types now 

 before us. 



In the first place we meet with what appears to be a 

 perfectly new development in the morphology of plants, 

 namely, the flower. That structure, however, turns out on 

 closer examination to be simply a cone the constituent leaves 

 of which have become variously modified, some coloured, 

 some remaining green, and others, i.e. those bearing the 

 sporangia, which are themselves considerably modified, very 

 much altered in shape and microscopic structure. We find 

 in the second place that certain of the sporangia those 

 which produce ovospores do not shed their contents, but, 

 covered over by the leaf on which they were produced, form 

 with the sporophyll itself what is commonly known as the 

 fruit. Indeed, we might briefly state the case thus : while 

 the fern and Selaginella shed their spores, a flowering plant 

 sheds its sporangia and their contents, and very often the 

 sporophylla also. 



Again, we find that there are many points of difference, 

 or, rather, advance in the structure of the fibro-vascular 

 strands, and in their mode of arrangement both in the stem 

 and in the root. The leaves also are found to possess, what 

 we may term, higher organisation, in virtue of there being 

 greater differentiation of parts and more division of labour. 

 The Angiospermcz, as the plants we are now considering 



