GLOSSARY. 



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umbilicus : a term applied to 

 the pillar-opening in univalve 

 shells ; also to the openings 

 at the base and top of the 

 quill of a feather. 



valvate : an arrangement of the 

 outer parts of the flower bud 

 where the edges meet but do 

 not overlap. 



venation : the arrangement of 

 the veins in a leaf. 



versatile : a mode of attachment 

 of anther to filament in which 

 the former has free movement 

 and swings readily, e.g. an- 

 thers of grasses. 



vertebrate : the division of the 

 animal kingdom which is 

 characterised by the posses- 

 sion of a backbone. 



whorl : a circle of similar struc- 

 tures, e. g. leaves or floral parts, 

 arising at the same level. 



xanthophyll : a yellow vegetable 

 pigment occurring in associa- 

 tion with chlorophyll. 



zygomorphic : divisible in one 

 plane only into two similar 

 parts, i.e. showing bilateral 

 symmetry. 



