532 



BOTANY 



TAUT II 



narrow, flat leaves and persist for several years. The tree is dioecious ; tlie flowers 

 are situated on the lower surface of the twigs and arise in tlie axils of the leaves 

 of the preceding year. The male flowers are invested at the base by a number 

 of scale-leaves and contain some 10 peltate stamens, each of which bears 5-9 

 pollen-sacs. The mode of opening of the sjiorangia is peculiar. The outer wall 

 splits at the base and along the side of each pollen-sac, so that the whole stamen 



771 



Pio. 502. — Taxiis bna-aia. A, branch with female flowers ; *, two ovules on the same shoot (iiat. 

 size); B, leaf with axillary, fertile shoot (x 2); C, median longitudinal secticju of a primary 

 and secondary shoot ; )', vegetative cone of the primary shoot ; a, rudiment of the aril ; c, 

 rudiment of the embryo-sac ; n, nucellus ; i, integument ; rn, micropyle (x 48). I'oisoxuus. 



resembles an umbrella turned inside out ; the pollen remains for a time in the 

 pocket- like depressions, from which it is removed by the wind. The female 

 flower usually develops singly as a secondary, axillary shoot of the ujipermost 

 scale leaf of a jn-imary shoot ; the apex of the latter is deplaned to the side and 

 does not develop further. Each flower consists of a single, atropous ovule with 

 one integument. The drop of fluid excreted from the micropyle of many Gymno- 

 s]ierms is especially well shown by the Yew. As tlie seed develops, a fleshy arillus 

 springs from its base and surrounds the luature .seed like a bright red cup. The 

 foliage and seed are poisonous, but the aril, which induces birds to distribute the 

 seed, is harmless. 



