LABOE4TORY STUDIES OF THE FLOWER 99 



Pinnately bi-, trt-, quadri-, or pluri-foliolate (that is, of two, three, 

 four, or several leaflets), as the case may be : these are terse ways of 

 denoting in single phrases both the number of leaflets and the kind 

 of compounding. 



XI. LABORATORY STUDIES OP THE FLOWER 



The object of the flower is the bearing of seed for the reproduction 

 of the plant. It is best to examine at once the seed rudiments with 

 the parts in which they are borne, and those equally important prod- 

 ucts, the pollen grains, which act upon the seed rudiments to make 

 them capable of growth into seed, as well as the organs which bear 

 the pollen. After that the less important, though more showy, parts 

 of the flower are to be studied. 



EXERCISE XXIX. THE RUDIMENTS OF THE SEEDS 



Look the flower over as well as possible, without pulling it to 

 pieces, to see what the various parts are like. Note in a general way, 

 without drawing, the number, arrangement, and varied shapes of the 

 parts. 



Remove the members at one side in order to get at the central 

 organ, the pistil. Cut this off at the end gradually until white, seed- 

 like bodies the ovules are brought to view. 



Cut down the sides wherever necessary in order to split off the 

 outer walls, so as to leave the ovules undisturbed and exposed to view 

 in their natural positions. "* 



Examine with the lens, noting: 



(1) the arrangement ; 



(2) the number of rows hi each compartment; 



(3) the attachment of the ovules; 



(4) the number of compartments. 



The hollow portion of the pistil is the ovary; its compartments 

 are termed cells. The middle part of the ovary, where the walls of 

 the cells meet, is the axis. The partitions between the cells are the 

 dissepiments. The surface where the ovules are attached in a cell is 

 the placenta ; if there are several cells there are several placentae. The 

 manner in which the ovules are placed, as concerns attachment, is the 

 placentation. If they are attached to the axis the placentation is 

 axile ; if to the walls of the cell, it is parietal. 



Add to your notes a few words describing the pistil in hand as to 

 the number of cells and th'e placentation. 



Taking up a fresh flower, for the moment, note how the pistil ends 

 above. The somewhat enlarged end with granular or loose tissue on 

 the surface is the stigma. Below this the pistil is often narrowed, so 



