CH. xvii MORPHOLOGY OF SEEDS AND FRUIT 



223 



Ovule, 

 Funiculus. 

 Integuments. 

 Micropyle. 

 Nucellus. 

 Embryo-sac. 

 Contents of sac. 



Seed, 



Funiculus. 

 Testa. 

 Micropyle. 

 Perisperm. 

 Embryo-sac. 

 Embryo and Endosperm. 



Examples of Various Kinds of Seeds. Some examples of the different 

 kinds of seeds will be useful : 



The ' Aril. The seeds of some plants have appendages 

 which may be variously produced from the funiculus, hilum, or 

 micropyle. Such new growths are called arils. In the Willow- 

 herb a tuft of hairs is produced which aids in the distribution 

 of the seeds. In the Water Lily the aril is produced from the 

 funiculus, and grows round the seed, producing an outer cover- 

 ing often mistaken for the integument. This method of the 

 formation of an aril also takes place in the Yew and Passion 

 flower. In the seed of the Castor Oil plant the aril appears as 

 a small ivart-like swelling at its base. The Willow produces a 

 tuft of woolly hairs formed from the funiculus, and hence called 

 a funiculus aril. Among other plants which produce an 

 aril Milkwort, Violet, Celandine, and Spindle-tree may be 

 mentioned. 



EXPT. 191. Examine the structure of the seeds given in the table 

 on p. 223. Note 



(i) The nature of the testa. 



(ii) The position of the hilum and micropyle. 



(iii) The kind of seed whether albuminous or exalbuminous. 



(iv) The nature of the endosperm or perisperm. 



(v) The number of cotyledons present. 



