CHAPTER XIX. 



The Study of Typical Fruits. 



214. A Berry, the Tomato.'^ — 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 thick- 

 ness of the epidermis (peel off 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 gelatinous, 

 slippery coating of each seed. Rub off this coating and then note the 

 wing-like margin around the 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 char- 

 acter, so the student will do well to spend a little more time on the 

 examination of such fruits as the orange or the lemon. 



215. A Sesperidium, 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 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 magnifying glass and count the minute 

 whitish raised knobs at the bottom of the saucer-shaped depression left 

 by the removal of the disk. 



Make a transverse section of the lemon, not more than a fifth of the 

 way down from the stigma end and note : 



(1) The thick skin, pale yellow near the outside, white within. 



(2) The more or less wedge-shaped divisions containing the juicy pulp 

 of the fruit. These are the matured cells of the ovary ; count these. 



(3) The thin partitions between the cells. 



» 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. 



