150 
THE FIRST BOOK OF BOTANY. 
ovules of a young apple. Of an unripe cucumber. 
Of an unripe tomato. Of any unripe fruit you see 
growing within reach. 
Observe the same plants when the fruit is ripe, 
and compare the aspect of the seeds with the appear¬ 
ance the ovules presented. 
Try to count the carpels in all the ovaries you ex¬ 
amine Observe whether they are grown together or 
not. Count the carpels shown in Fig. 168. Do you 
see the three white lines passing outward from the 
center in this picture ? Should you judge that the 
carpels from which this picture was taken were grown 
together? Search, among plants that are going to 
seed, for ovaries resembling this one. 
EXERCISE LII. 
Sutures and Dehiscence . 
Look among the ripe and dry pea and bean pods, 
upon the dry vines, for those that have begun to open. 
Examine the edges of the separate parts. Do you 
see something like a joint where the two parts were 
united? Compare them with Fig„ 243 0 
DehisAence. —The opening of a seed-vessel at 
maturity. See Fig. 243. 
Sut'ure. —A seam. The line along which dehis- 
cence occurs, and so permits the escape of the seeds. 
Ven'tral Suture.— The inner suture of a carpel. 
The one looking toward the center of the flower. In 
Fig. 243, it is the suture along which the ovules are 
attached. 
