AERANGEMENT OF AIR-CANALS IN STALKS OF NYMPHiEAS. 841 



are encircled by one or more rows of smaller tubes, each row generally 

 containing twice as many tubes as that immediately interior to it. As 

 illustrations of this group may be mentioned N. ccBrulea, cyanea, 

 scutifolia, guineensis, hlancla, ampla, mexicana, amazonum, micrantha, 

 stellata, and sometimes tuberosa and alba, &c. 



Fig. 343. — Nymph^ea devoniensis, of the Lotus section, with two large air-canals 

 in the leaf-stalk and four smaller ones, and with six large canals in the tlower-stalk 

 radiating from the centre ; 2, stamen ; 3, stigmas. (From Bot. Mag. tab. 4,605.) 



The third group includes the Lotus section, comprising N. Lotus, 

 dentata, devoniensis, &c., characterised by the presence of two relatively 

 very large air-canals in the leaf-stalk, whilst those of the Hower-stalk 

 radiate from the centre as in the Cyanea section, and several of M. Latour- 

 Marliac's finest hybrids. (Fig. 343.) 



