CHAPTER XVII 

 THE STUDY OF TYPICAL FRUITS 



229. A Berry, the Tomato. 1 Study the external form of the 

 tomato, and make a sketch of it showing the persistent calyx and 

 peduncle. 



Cut a cross-section at about the middle of the tomato. Note the 

 thickness of the epidermis (peel oif a strip) and of the wall of the 

 ovary. Note the number, size, form, and contents of the cells of 

 the ovary. Observe the thickness and texture of the partitions 

 between the cells. Sketch. 



Note the attachments of the seeds to the placentas and the gelati- 

 nous, slippery coating of each seed. 



The tomato is a typical berry, but its structure presents fewer 

 points of interest than are found in some other fruits of the same 

 general character, so the student will do well to spend a little more 

 time on the examination of such fruits as the orange or the lemon. 



230. A Hesperidium, the Lemon. Procure a large lemon which 

 is not withered, if possible one which still shows the remains of the 

 calyx at the base of the fruit. 



Note the color, general shape, surface, remains of the calyx, 

 knob at portion formerly occupied by the stigma. Sketch the fruit 

 about natural size. Examine the pitted surface of the rind with 

 the magnifying glass and sketch it. Remove the bit of stem and 

 dried-up calyx from the base of the fruit; observe, above the calyx, 

 the knob or disk on which the pistil stood. Note with the magni- 

 fying glass and count the minute whitish raised knobs at the bottom 

 of the saucer-shaped depression left by the removal of the disk. 

 What are they ? 



1 Fresh tomatoes, not too ripe, are to be used, or those which have been kept 

 over from the previous summer in formalin solution. The very smallest 

 varieties, such as are often sold for preserving, are as good for study as the 

 larger kinds. 



217 



