66 



LABORATORY AND FIELD EXERCISES 



ovary ? Are there budlike outgrowths from the 

 enlargement of the ovary wall in your section ? 

 What is the shape of these buds, or enlarge- 

 ments? Draw the two or three sections of the 

 ovary which you have made. Label the parts after 

 you have 

 studied "the 

 text and 

 Fig. 220. 



5. The fruit. Study 

 both the exter- 

 nal and the in- 

 ternal structure 

 of the fruit of 

 the mandrake 

 or other plant 

 examined. Do 

 you find the 

 same parts in 

 the fruit as 



FIG. 18. Section of a portion of a wheat kernel 



p, pericarp; t, seed coat; al, aleurnne, or ni- 



trogenous layer of the endosperm ; //, nuclei ; 



st, starch-storing cells of the endosperm. 



After Strasburger 



you did in the 

 pistil ? What 

 forms the in- 

 terior of the fruit ? Where are the ovules ? the placenta ? 

 the ovary wall? What relation has the fruit to the 

 pistil ? Define a fruit. Draw a sectional view of the fruit 

 to show all of its parts in their proper relation. Label 

 the parts, using the same terms as were used for similar 

 parts of the ovary (see text discussion and Fig. 221). 

 6. Supplementary studies : gametogenesis, fertilization, and 



development. 



a. Microscopic structure of pollen. Mount large pollen 

 grains taken from some liliaceous plant, like the 



