species, namely of Oenone Imthurni Goebel and Mou- 

 rera fluviatilis Aubl. Of eight other species only a few 

 stages of the development were examined, and of Tristicha 

 hypnoides Spr. I only had the ripe seeds. 



It soon became évident that the whole development of 

 the ovule in this order départs very widely from the 

 ordinary type of Angiosperms, but that within the limits 

 of the order there is an extraordinary degree of unifor- 

 mity, so that the différences between the species. which 

 hâve been investigated, are so slight, that thoy may be 

 passed over in silence in this preliminary notice. The 

 description which follows, therefore applies to ail the 

 species. 



The ovules are anatropous ; in the youngest stage ex- 

 amined (flg. 1) the curvature had already taken place. In this 

 stage the nucellus was still alone présent and consisted 

 of a central row of four cells surrounded by a single 

 layer of peripheral cells. Of the central row the upper- 

 most cell, which is therefore still surrounded by a cap of 

 epidermal cells, becomes the spore mother-cell. Accordingly 

 this cell is not only soon distinguished from ail the other 

 cells of the nucellus by its size, but also by its dense 

 protoplasmic contents and by its large nucleus. The subsé- 

 quent behaviour of this spore mother-cell will Ijo furtlier 

 discussed below. 



We may now consider how the integuments are formed. 

 The outer one arises first and hère we find the first dévia- 

 tion from the normal course of development in Angiosperms. 

 This integument simply arises as an annular fold on the 

 nucellus with which it remains connected by the chalaza, 

 while for the rest it grows round pretty loosely (flg. 2). 

 Finally there remains at the point, where its borders meet, 

 a very narrow micropyle, which can only be seen properly 

 in truly medial sections (fig. 3, 11). 



