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A TEXTBOOK OF THEORETICAL BOTANY 



this secondary axis. In the axil of the penuhimate bract {i.e., the eighth, 

 counting downwards from the apex of the secondary shoot) there is a bud 

 which was formerly regarded as the apex of the primary axis, but which is now 

 known to be an arrested secondary shoot which sometimes develops and 

 produces a second ovule. The vegetative apex of the primary shoot seems to 

 be suppressed, but occasionally it proliferates after a seed has been formed 



Micropyle 



Nucellus 



- Integument 



Embryo sac 



Cupule 



Bract 



Fig. 705. — Taxus baccata. Longitudinal section of the 

 ovule and ovuliferous branch. 



and again produces a secondary axis and an ovule in the following year. The 

 position of the first ovule is then marked by a lateral scar. 



The ovule is somewhat flattened, transversely to the uppermost pair of 

 bracts, and the ripened seed is therefore oval in section, with two lateral ribs. 

 Three and four ribbed seeds also occur as exceptions. There is a single, 

 thick integument, which forms a rather long micropylar canal above the 

 nucellus (Fig. 705). Two vascular bundles supply this integument, running 

 along the lateral ribs. These bundles arise by the fusion of two pairs in the 

 stalk of the ovule, one pair branching from the traces of the penultimate pair 

 of bracts and the other pair from those of the uppermost pair of bracts. 



Immediately below the integument there arises a ring-like swelling which 



