ANGIOSPERMS. 



197 



They are in fact spores, the microspores of the trillium, and 

 here, as in the gymnosperms, are better known as pollen. 



325. The stamen a sporophyll. — Since these pollen grains 



are the spores, we would 

 infer, from what we have 

 learned of the ferns and 

 gymnosperms, that this 



Fig. 176. 



Sepal, petal, stamen, and pistil of Trillium 



grandiflorum. 



member of the flower which 



bears them is a sporophyll ; 



and this is the case. It is in 



fact what is called the micro- 



sporophyll. Then we see also 



that the anther sacs, since they 



enclose 'lie spores, would be the sporangia 



(microsporangia). From this it is now quite 



clear that the stamens belong also to the leaf 



series. They are just six in number, twice the 



number found in a whorl of leaves, or sepals, 



or corolla. It is believed, therefore, 



that there are two whorls of stamens 



in the flower of trillium. 



326. Gynoecium. — Next above the 

 stamens and at the centre of the flower 

 is a stout, angular, ovate body which terminates in three 

 long, slender, curved points. This is the pistil, and at 



Fig. 177. 

 Trillium grand- 

 diflorum, with 

 the compound 

 pistil expanded 

 into three leaf- 

 like members. 

 At the right 

 these three are 

 shown in detail. 



