184 ELEMENTS OF BOTANY. 
natural position and the funiculus or stalk by which each is attached to 
the placenta ; compare Fig. 176. 
Make a cross-section of another pod, through one of the beans, sketch 
the section and label the placenta (formed by the united edges of the 
pistil leaf), and the midrib of the pistil leaf. 
Break off sections of the pod and determine, by observing where the 
most stringy portions are found, where the fibro-vascular bundles are 
most numerous. 
Examine some ripe pods of the preceding year,! and notice where the 
dehiscence, or splitting open of the pods occurs, whether down the pla- 
cental edge, ventral suture, the other edge, dorsal suture, or both. 
217. An Akene, the Fruit of Dock. — Hold in the forceps a ripe fruit 
of any of the common kinds of dock,? and examine with the magnifying- 
glass. Note’ the three dry, veiny, membranaceous sepals by which the 
fruit is enclosed. On the outside of one or more of the sepals is found a 
tubercle or thickened appendage which looks like a little seed or grain. 
No use is known for this. 
Of what use are the sepals, after drying up? Why do the fruits cling 
to the plant long after ripening ? 
Carefully remove the sepals and examine the fruit within them. What 
is its color, size, and shape? Make a sketch of it as seen with the 
magnifying glass. Note the three tufted stigmas, attached by slender 
threads to the apex of the fruit. What does their tufted shape indicate ? 
What evidence is there that this seed-like fruit is not really a seed ? 
Make a cross-section of a fruit and notice whether the wall of the 
ovary can be seen, distinct from the seed coats. Compare the dock-fruit 
in this respect with the fruit of the anemone, shown in Fig. 169. Such 
a fruit as either of these is called an akene. 
2 Which may be passed round for that purpose. They should have been saved and 
dried the preceding autumn. 
2Rumex crispus, R. obtusifolius, or R, verticillatus. This should have been 
gathered and dried the preceding summer. 
