YEW REPRODUCTIVE ORGANS 259 



and their own basal portion, from the cavity of the 

 endosperm. 



4. The rest of the seed is usually carried upwards 

 on the apex of the cotyledons, which, with the 

 hypocotyledonary stem, elongate greatly. 



5. The plumule develops, forming numerous acicular 

 leaves. 



Note that the cotyledons turn green while still 

 protected from the light, below the soil, and within 

 the testa. 



Compare the reproductive organs of the Yew (Taxus baccata) : 

 in this plant pollination takes place late in March, and the seed 

 attains maturity in the course of the same year. 



Examine male flowers in early spring, and observe 



1. Their axillary position. 



2. The scale-leaves, which are inserted at the base of the 

 short axis. 



3. The staminal leaves, which occupy the upper part of the 

 axis, each bearing a peltate head with 4-5 pollen-Sacs. 



Moisten a little of the pollen with alcohol, and mount in water : 

 observe the simple form of the grains, and the absence of the 

 wings. 



Examine also the female flowers, which are produced on 

 different plants' from the male organs, the species being dioacious : 

 they appear as solitary axillary buds, consisting of a single central, 

 and apparently terminal ovule, surrounded by a number of small 

 imbricated scales : the micropyle may be easily recognized at the 

 apex of the ovule, and at the receptive period a sticky drop may 

 be seen to have exuded from it. 



Cut median longitudinal sections through one of these ovules, 

 taken late in March, and observe the axis (a secondary lateral 

 axis) terminated by the nucelleus : this is surrounded by a single 

 integument with an obvious micropyle : a single larger cell, 



s 2 



