LAB0B4T0Rr STUDIES OF THE FLOWER 99 



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

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

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

 of compounding. 



XI. LABORATORY STUDIES OF THE PLO^WBR 



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 w^ell as the organs which bear 

 the pollen. After that the less important, though more show^y, 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 w^ay, 

 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 gradiially until white, seed- 

 like bodies — the ovules — are brought to view^ 



Cut down the sides w"herever 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 row^s in 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 placentce. 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 the placentation. 



Taking up a fresh flow^er, for the moment, note how the pistil ends 

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

 the surface is the stigma. Below this the pistil is often narrow^ed, so 



