218 PRACTICAL BOTANY 



embryo as before, viz. two flattened cotyledons, the 

 cylindrical radicle, and very small plumule. 



Longitudinal sections should be cut of the mature 

 seed of Caltha for microscopic observation under a low 

 power, and the relative positions of the firm testa, the 

 endosperm, and embryo, are to be observed, together 

 with details of their structure. 



FRUIT, SEED, AND EMBRYO. 



(B) Monocotyledons. 



II. Soak fruits of the Maize (Zea Mais) in water 

 for several hours. The fruit is a caryopsis, and results 

 from the development of both ovule and ovary; its 

 form is compressed conical, the apex of the cone 

 being the basal point of attachment of the fruit. 



Strip off the external coat of the fruit : this re- 

 presents both the wall of the ovary and the integu- 

 ment of the ovule. 



Distinguish in the body of the fruit which 

 remains 



1. A lateral, smaller, white portion : this is the 

 embryo. 



2. A larger yellow part, which forms the greater 

 mass of the fruit : this is the endosperm. 



Separate the embryo from the rest, and note its 

 shape. 



III. Cut longitudinal sections of the fruit so as 

 to traverse the embryo in a median plane : mount in 

 glycerine, and examine with a low power : observe 



i. The coat of the fruit, consisting of two layers, the 



