ii2 LABORATORY PRACTICE CHAP, xxvn 



4. Make a sketch of the fruit studied. 



5. Why do these fruits remain hard and green until the seeds 



are nearly ripe and then become soft and bright- 

 colored? 



II. Cut a ripe Peach, Cherry, or Plum into two longitudi- 

 nal halves and notice : 



1. The outer skin of the pericarp. 



2. The fleshy middle portion of the pericarp, called the 



sarcocarp. 



3. The inner stony portion of the pericarp, the putamen, 



enclosing 



4. The seed, whose seed-coats are thin and delicate. 



5. Make a sketch of one of the cut surfaces. 



III. The drupes just studied are all formed from the 

 ovary of a simple pistil, whose ovary was one-celled and one- 

 seeded. Drupes occur also in the Huckleberries, Bear- 

 berries, Manzanitas, etc., but contain several putamina. In 

 such cases they are distinguished from berries with some 

 difficulty, the putamina looking much like seed-coats. 



IV. The Berry. Take a Cranberry, examine it care- 

 fully, and notice : 



1. The general shape, size, and color. 



2. The short stalk (or the place where it was attached). 



3. The four blunt teeth surrounding a hollow at the opposite 



end. (These are the tips of the sepals which are 

 adherent to the ovary and help to form the pericarp 

 of the fruit.) 



4. Make a sketch to show these characters and label. 



V. Cut the berry being studied across at the equator and, 

 examining one of the cut surfaces, notice : 



