ANATOMY OF PLANTS. 207 



325. 



The structure of nectaries, and the apparatus belonging to 

 ihem, corres])onds, in this respect, with die structure of die 

 corolla, that the nectarilyniata and the nectarotheca? are often 

 parts of the corolla, or such likenesses of the parts of the co- 

 rolla, that we sometimes hesitate to which of the organs they 

 should be assigned. In order to be convinced of what has 

 now been stated, we may examine the nectarilymata of Phy- 

 lica, (Tab. II. Fig. 15.) ; of Agathosma, (Tab. II. Fig. 

 ^22.) ; and of Biittnera, (Tab. IV. Fig. 18.) The proper 

 nectaries, in the strict sense of the word, are cellular or glandu- 

 lar organs, which we find on the receptacle, or at the base of 

 the filaments. 



326. 



If we attend to the appearance of the corolla in the differ- 

 ent families of plants, we observe, in those of the simplest and 

 lowest organization, that there is either no trace at all of this 

 organ, or a feeble one ; but where it does shew itself, it is no- 

 thing but a colourless scale, or it consists of a fine and very 

 pellucid membrane. Coloured coverings for the sexual 

 parts, first appear in the Musci frondosi, which, beside these, 

 have also a permanent cap, by which the fruit is covered till 

 it be perfectly ripe. In the Piperea?, and most of the 

 Naida?, we find scarcely any thing but some fine scales below 

 the sexual parts, which it is difficult to consider as representa- 

 tives of the corolla; (Tab. III. Fig. 4, 5.) The Aroideag 

 supply the want of the corolla by sheaths, which are often of a 

 beautiful colour, and from which the spadix projects, or here 

 and there some white hairs arise, which may be considered as 

 the representatives of the corolla ; (Tab. II. Fig. 11.) In 

 the Cyperoidae there are also some scales only ; whilst, in the 

 Grasses, there are fine pellucid membranes, which we must 

 regard as the corolla. But the outermost valves are some- 

 times coloured, as in Triodia, J vena versicolor, and Ses- 

 leria coerulea. The Restiacea3 and Junceae begin to exhibit 

 a regular corolla, which, in some genera, is beautifully co- 

 loured. The colouring of the corolla proceeds through the 



