52 



BOTANY 



apple, then, appears to be formed from some other parts of the fiower. 



Botanists are undecided as to whether it is calyx tube, receptacle, or part 



of both structures.* 



Draw a cross section of an apple to show 

 the above points. In a longitudinal section 

 the relation of the fruit to the flower is better 

 shown. The stem was the peduncle of the 

 flower; the ovary wall, placenta, and seeds 

 may easily be seen. In young specimens 

 the funiculus, a thread attaching the seed 

 to the placenta, may be found. A short 

 distance outside the ovary wall is seen a 

 faint line. This is composed of somewhat 

 stringlike structures, the tubes such as we 

 found in the strings of the string bean. 

 These bundles of ducts are called the fibro- 

 vascular bundles. It is through these ducts 

 that the apple has received most of the 

 food material which was used to form the 

 fruit. We shall learn more about the struc- 

 ture of the fibrovascular bundles in the study 

 of the stems of different plants. Draw a 



longitudinal section of the apple, natural size. 



Other fruits, built on the same plan of structure as the apple, are the 



pear, quince, and hip. These fruits are classed as pomes. 



Pepo. — Another fruit of somew^hat similar structure as the pome is the 

 pepo. The pumpkin, gourd, and squash are examples. Cut a squash open 

 in cross sections. The ovary wall can be made out close to the numerous 



Longitudinal section of a pome; 

 p, peduncle; /, (ibrovascular 

 bundles; s, seeds; pi, placenta; 

 c, carpel. 



Cross section of a cucumber. Note 

 the number of locules. How 

 and where are the seeds at- 

 tached ? 



Cross section of a green pepper ; 

 a berry. How many locules 

 has the ovary? Note the ar- 

 rangement of the seeds. 



seed which fill the locules of the ovary. How many locules are there in the 

 squash ? The outer fleshy part and the rind grow from the receptacle of the 



' See Hvinter and Valentine, Manual, page 73. In this and other suggestions for 

 laboratory work it is expected that the teacher will select from the following pages 

 only a portion of the given material. 



