200 THE FLOWER 



the inner or ventral sutures, so that there are only three 

 true carpels. Select a flower that has begun to wither, so 

 that the ovary is well developed, cut a cross section near 

 the middle and try to make out the number of cells, or 

 internal divisions. Make an enlarged sketch of the sec- 

 tion as it appears under the lens (see Fig. 383), showing 

 the arrangement of the parts, also a longitudinal section 

 ,(Fig. 382) showing their relative vertical position. Label 

 the little round bodies that represent the undeveloped seeds 

 ovules, the surface to which they are attached, placenta, 

 and the cavities, or divisions containing them, cells, or 

 loculi (singular, loculns}. How many of these are there ? 

 Compare these sketches of the ovary with your drawings 

 of dehiscent fruits in Sections 93-109. What correspond- 

 ences do you notice between them ? 



As the ovary is merely an undeveloped fruit, and the 

 ovules immature seeds, their structure is the same as that 

 of these parts, and the same terms are used in describing 

 them (Sees. 73-79, and 93-109). 



288. Numerical Plan. Now make a horizontal diagram, 

 after the model given in Figure 384, showing the manner of 



attachment of the different cycles sepals, 

 petals, stamens, and pistils, the number of 

 organs in each set, and their mode of 

 alternation with the organs of the other 

 cycles. Notice that in the star-of-Bethle- 

 384 Horizontal ^ em an d si m il ar flowers, the parts of each 

 diagram of a flower set are in threes, or multiples of three. 



of the lily kind. TM- n , , -11 r i 



The dot represents Thls ls called the numerical plan of the 

 the growing axis flower, and is the prevailing number among 

 monocotyledons. It is expressed in botani- 

 cal language by saying that the flower is trimerous, a word 

 meaning measured, or divided off into parts of three. 



289. Vertical Order. Next make a vertical diagram of 

 your specimen after the manner shown in Figure 372, and 

 note carefully that the ovary stands above the other organs 

 (this is true of all the lily family), and is entirely separate 



