2o8 THE FLOWER 



Remove a stamen and sketch it as it appears under the 

 lens. Notice the attachment and shape of the anthers. 

 Are they all of the same color ? How do you account for 

 the difference, if there is any ? Is the position of the 

 pistil and stamens such that the pollen from the anthers 

 can readily reach the stigmas without external aid ? 

 Examine the pistil in flowers of different ages, and see if 

 the stigma is mature (that is, moist and sticky) at the 

 same time that the anthers are discharging their pollen. 



Draw a cross section of the ovary and try to make out 



with a lens the number of cells, or loculi. If you can not 



succeed, turn to the cross section of the pome made in your 



study of fruits, and that will settle the question, since the 



® U fruit is merely a 



~=sv y/^'^^x z^^*"^^'^ ripened ovary. 



if^i / \ / \ Examine the 



I \ It I overlapping of 



/ \^^ J X X the petals in the 



401 402 403 bud, and diagram 



401-403. — Types of imbricated aestivation common their Sestivation 

 among dicotyledons (after Gray). (FiffS 40I-40^) 



Compare this with the diagrams of leaf arrangement in 

 Sections 50-52, and decide to which it corresponds. 



Diagram the plan of the flower in cross and vertical 

 section. How many parts are there in each set .'' Can you 

 readily tell the number of stamens .■" When the individuals 

 of any set or cycle of organs are too numerous to be easily 

 counted, like the stamens of the apple, pear, and peach, 

 or the petals of the water lily, they are said to be indefinite. 

 It is very seldom that perfect symmetry is found in all 

 parts of the flower. The stamens and pistil, in particular, 

 show a great tendency to variation, so that the numerical 

 plan is generally determined by the calyx and corolla. 

 Where the parts are in fives, as in the pear, quince, wild 

 rose, etc., the flower is said to \>& pentamerous, or in sets of 

 five. 



After drawing the diagrams, write in your notebook 

 answers to the following questions : — 



