84 



ELEMENTS OF BOTANY. 



Bearing in mind, however, tlmt all the lloral or^j^ans are but trans- 

 formed Iciith'ts of k'at'-buds, it in not difficult to understand the Htructure 

 of the jnstil. Let us take, for example, a jjea-pod, which is only a siniiile 

 pistil that has been fertilized and undergone subsequent doveloi)ment, 

 ■without any essential chanpfo of form. Si)Ut it open on the side to which 

 the seeds arc attached and Hproa<l it out as nearly flat aspossil)le. We ob- 

 serve, then, that it has the general form of a leaf witli a stalk like a petiole 

 and a inid-vein which continues to the apex, while on the margins are i:)laced 

 the seeds. Now this pod is but nn altered leaflet, which was folded in- 

 ward and united at the margins, and had developed along this line of 



Flo. Cl.— A ray florot < f a head 

 (compound flower). 



;W 



Fio. 62.— A pistil. 

 o "H tlio ovnry, »///. 

 tlic i-tjle, atig. tlio 

 stigiim. The ovnry 

 rests upon the ro- 

 ct'ptnclo (>•), which 

 teniiinateB llie po- 

 diincio (p). 



Pio. f)0.— A disk or tiibulnr floret of a hend (compound flower), showing the ixnthcrs iinitL>d into one set 

 (syngeiu'sions). Mafrnilieil. 



union a number of ovides. At the apex the stigma was placed, and 

 through this fertilization was effected, as will be seen later. Such is the 

 general plan upon which the simple pistil is constructed ; but as the 

 leaves of plants exhibit an endless variety of forms, so naturally would the 

 leaflets Avhose transformations produce pistils, and hence the pistils also. 

 Again, the pistils are very often compound — that is, made up of from two to 

 many simple ones growm together. Suppose, for example, a circle of five 

 leaflets stand in the centre of a bud, which are to be transfonned into a 

 compound pistil. The margins of each Avould be folded in and united, to 

 form simijle pistils ; then the sides of each, coalescing with those of its 





