128 THE OAK 



from the outermost lower pair (1) of scales (stipules) to 

 the innermost upper pair (21) with their leaf. 



If we suppose the female inflorescences removed, the 

 above diagram will serve to represent the lateral buds 

 which develop male inflorescences only, or if we sup- 

 pose the three bracts F, a, and /3 away, it would serve 

 for a terminal bud. 



Each single female flower stands in the axil of a 

 minute scale on the floral axis, as said, and its general 

 structure has been described. When the pollen grains 

 have been dusted on to the trifid stigma, about the end 

 of May or beginning of June, each grain germinates 

 and sends a minute tube down the style, and this pollen- 

 tube soon reaches the cavity of the ovary, and its end 

 becomes applied to one of the ovules. While the 

 pollen-tube is descending the style, the ovules have 

 arisen as minute cellular outgrowths from the angles of 

 the three chambers of the ovary (fig. 34, d). There are 

 two in each chamber. Each ovule is at first a mere 

 solid lump of cells (nucellus), which curves and becomes 

 enveloped in two thin investing layers, called integu- 

 ments, as shown in the figures A-D (fig. 35). Inside 

 the solid nucellus, n, of the ovule there soon arises a 

 small cavity filled with nucleated protoplasm, and termed 

 the embryo-sac, e, because the embryo is to be deve- 

 loped in it. 



This embryo-sac contains, among other structures, 

 a minute, nucleated, naked mass of protoplasm, called 

 the oosphere, or egg-cell. The pollen-tube has carried 



