After the outer integument has already surrounded half 

 the ovule, the inner one begins to develop. Cell divisions 

 are seen to occur in a few epiderma] cells of tlie nucellus, 

 immediately above the point of attachment of the outer 

 integument (fig. 2). Thèse divisions take place in such a 

 manner, that a wall arises in one of the basai cells of 

 each longitudinal row of the epidermis; this wall forms 

 an angle of 45' with the longitudinal direction of the 

 ovule, so that each of the cells is divided into two. The 

 upp(?r half remains an epidermal cell of the nucellus, 

 while the lower half develops to form the inner integu- 

 ment (fig. 3). In a transverse section the number of epi- 

 dermal cells, counted on the periphery, is seen to be 5, 

 occasionally 6 or 7 (fig. 13). At first the inner integument 

 will therefore show in transverse section an equal number 

 of cells. Dividing walls soon arise, however, which make 

 this inner integument two cells thick (fig. 3, 6, 11, 12, 14). 

 More than two layers do not develop, as no further tangen- 

 tial walls are formed, but other walls, hoth radial and 

 transverse to the long axis of the ovule are developed. 

 Especially the number of radial walls is very différent in 

 the two cell layers ; it is large in the outer layer, but on 

 the other hand small in the inner layer. As a resuit, the 

 number of cells of the inner layer of the inner integument 

 is generally little more than five, when counted in trans- 

 verse section (fig. 12). When afterwards the cells of the 

 inner integument increase in size and often acquire di- 

 mensions, which make them very noticeable, it is the 

 inner cells which are especially large. This growth 

 is often accompanied by strong thickening of the walls 

 (fig. 11). 



The transverse walls, which arise in the cells of the 

 inner integument, enable the latter to grow longitudinally. 

 In this process the top of the nucellus remains free how- 



