OF THE ORGANS. 



79 



In the seeds of many of the Leguminous plants, a small ca- 

 vity appears under the umbilicus, called micrcypyle, but its 

 use is unknown. 



Chalaza is the place in the interior membrane of the 

 seed, where the funiculus umbilicalis passes into the seed. 

 Sometimes this is at a distance from the umbilicus, and it is 

 even, as in the seed of the Citron (Tab. 1. Fig. 1. 2.), placed 

 opposite to it. 



121. 



When we open the seed, we find the embryon either sur- 

 rounded by albuminous substance {albumen, perispermium, 

 endospermium), or this substance lies in the centre of the 

 curved embryon, as in some of the Polygoneae and Caryo- 

 phyllese ; or it lies on the side of it, as in the Grasses and in 

 the grains of Corn ; (Tab. I. Fig. 3. 11. 20.) But this sub- 

 stance is often entirely wanting, that is, when the future plant 

 being already perfectly evolved, fills the seed ; (Tab. I. Fig. 

 1. %) 



Seeds which have albuminous substance are called alhumi- 

 noscE, and those which want it exalbuminos^e. 



In some imperfect seeds, there is an intermediate body be- 

 tween the albuminous substance and the embryon, which in 

 the Grasses is called scidellum (Tab. I. Fig. 11.), and in the 

 Scitamineas vitellus, (Tab. I. Fig. 3.) In the latter it sur- 

 rounds the whole embryon. 



The embryon, or future plant, is either unevolved, when it 

 resembles a small point, or a short thread ; or it is evolved^ 

 and then we distinguish on it the two seed lobes {cotyledones)^ 

 the plant itself (plumuld), and the root (rostellum or f^adicu^ 

 la) ; (Tab. I. Fig. 1^ 2. 5.) The direction of the last, com- 

 monly towards the umbilicus, may, however, be either up- 

 wards or downwards, according as the seed is placed. In the 

 former case the embryon is called inverted (inversus), be- 

 cause it has the opposite direction with respect to the fruit, 

 but not with respect to the seed. In the latter case, the em- 

 bryon is said to be erect (erectus), (195.) 



