STRUCTURAL BOTANY. 25 



The following Key may serve to distinguish them : 



1. Names of flat forms derived from their whole 

 outline^ which, if it has sinuses, must he corrected 

 hy uniting mentally all its prominent points hy a 



line (see Cut II., Figs, a — k) 2 



Names of flat figures derived not only from the 

 whole outline, hut also from the shape of the hase 

 — that is, thejyart hy which the organ is attached 

 to a support, and the form of the apex — that is, the 

 part opposite the hase (see Cut III., Figs, a — o). . . 12 



2. By comparing the longitudinal and transverse di- 



mensions with each other 3 



By imagining a centre or a middle line (x) on 

 the surface of the fig-ure, and then halving the 

 distance thence to the corrected outline 11 



3. Transverse dimensions, all of equal length, as in 



the cross-sections of terete bodies orhicular 



(II, Fig. a) 

 Transverse dimensions of unequal lengtli 4 



4. Greatest diameter in the middle of the figure 5 



Greatest diameter not in the middle 6 



5. Figure about twice as long as wide, forming a 



short ellipse elliptic, or oval (b) 



Figure three or four times as long as wide, form- 

 ing an elongated ellipse ohlong (c) 



6. Greatest diameter in the lower third of the figure . . 7 

 Greatest diameter in the upper third of the fig- 

 ure, and the latter longer than wide 9 



7. Figure longer than wide 8 



Figure half as long (high) as wide, rounded above, 



and furnished with a roundish sinus below, 



reniform, or kidney-shaped (f) 



8. Figure twice as long as wide ovate (d) 



