204 HORTICULTURE FOR SCHOOLS 



In warm regions where the air is too moist for the successful 

 growing of the Smyrna or other white figs, dark figs are grown. 

 Throughout the southern states, quantities of figs are pro- 

 duced, which are used and shipped fresh, made into preserves, 

 or canned. Figs in the canned, preserved, and dried forms, 

 are delicious and wholesome foods. 



297. Other semi-tropical fruits grown in some parts of 

 the United States are the guava, feijoa, loquat, jujube, 

 persimmon, pomegranate, and avocado. Although all of 

 these are produced to some extent, lack of space forbids a 

 description of them in this book. 



EXERCISES 



EXERCISE I. Citrus fruits. 



Materials. At least one each of the following fruits: Washington 

 Navel orange, seedling orange, lemon, grapefruit. 



Procedure. Sketch each of the above fruits bringing out typical 

 differences in size and structure. Note the oil glands on the surface 

 of the fruit. Make a transverse section through the center of each 

 midway between stem-end and apex. Make a sketch of this section 

 showing the location of segments and the arrangement of cells within 

 the segments. 



Make another transverse section through the center of the Navel 

 orange and sketch, bringing out similarities between the Navel and 

 the original fruit. It may be mentioned parenthetically that the Navel 

 is itself an orange within an orange. 



In the drawings already made, indicate in the case of those fruits 

 bearing seeds the points of attachment of the seeds. Note manner in 

 which fruit was separated from the tree. Note especially the way the 

 cut was made and see if you can detect any sign of decay about this cut. 



EXERCISE II. Comparative amount of acid in orange and lemon. 



Materials. Orange and lemon, glass beaker, two graduated burettes, 

 standard alkali solution, 1 phenol indicator, lemon squeezer, wire 

 strainer. 



Procedure. Extract juice from orange, strain out coarse materials, 

 pour into burette, measure out 20 c.c. of juice, and add a few drops of 



* To the Instructor: Make up standard alkali solution by adding 6.25 

 grams sodium-hydroxide to 1000 c.c. of water. 



