84 



THE TORUS 



(Fig. 305), although most of the enlargement here seen, as in the next, 

 is the accrescence of fructification. The disk of the strawberry (Fig. 

 304) is similar, but its pistils are partly immersed. In the rose, a 

 related plant (Figs. 59 and GO), the form is modified by the elevation of 

 the margins, instead of the center, so that a cup-shaped disk is formed, 

 the pistils attached over its inner surface. In the cherry (Fig. 58) the 

 disk is thin and lines the calyx-tube, the pistil being free. In the apple 

 there is a similar disk lining the calyx-tube, and it, at maturity, is 

 thick, fleshy, and edible, and encloses the five pistils. In the Magnolia 

 (Fig. 251) the torus is vertically much elongated and at the same time 



Fig. 260. Saucer-shaped disk of Pseudima. 261. Similar disk of Allophyhts, but irregular and uni- 

 lateral. 262. Disk with two lobes coherent. 263. Cupulate, sinuate-margined disk of Hippocratea. 

 264. Disk of Xanthoceras, of five distinct horns. 265. Cupulate disk with lobed margin. 266. 

 Campanulate disk of Santalum, adnata to calyx-tube. 



much thickened, the pistils adnate along its surface. In the Nelumbo, 

 the torus (Fig. 252) is enlarged into a top-shaped or Turbinate body, 

 with the pistils embedded in the flat upper surface. Instead of thus 

 occupying a hj-pogynous position, the disk may be projected between 

 any two of the circles, and it may be wholly or partly adnate to either 

 (Fig. 266, a), or to both of them, or it may be entirely free. When 

 adnate to both circles it is plain that it becomes responsible for the 

 existing adnation between the latter. It may then exist only at the 

 base, or it may entirely fill up the interspace between the parts and even 

 become epigynous, so that the ovary is immersed in it or buried under- 

 neath it (Fig. 254, a) . The adnate disk may be shorter or longer than 



