60 IfRUCTlFlCATION, 



corcule, which they nourish until it has taken sufficient 

 root to support itself from the earth. 



Observation. The cotyledons are commonly two in number, as 

 in the Bean. They rise out of the ground with the plume, and 

 become the Seminal leaves, (folia seminalia) PI. 16, fig. 10, still 

 supplying nourishment to the young plant, and acting as lungs to 

 it by permitting the juices to be changed in them by the action of 

 light and air. 



From their Cotyledons Plants are denominated 



1. Acotyledonous, (acotyledones) supposed to have no 

 cotyledons. Ex. Ferns. 



2. Monocotyledonous, (monocotyledones.yPL 16, fig. 

 7. Having one cotyledon or lobe. Ex. Grasses. 



3. Dicotyledonous, (dicotijledones.) PI. 16, fig. 8. 

 Having two. Ex. Bean, Pea. 



4. PoIycotyledonouSj (polycotyledones.) PL 16, fig. 

 9. Having several. Ex. Pine and Fir. 



3. SKIN, (testa) envelopes the other parts, giving 

 them their proper shape ; for the skin is properly 

 formed while they are a homogenous fluid. 



Observation. 1. This is sometimes lined with a fine and delicate 

 membrane. 



2. ^There is in some cases a loose coat (arillus) external to the 

 skin, which generally falls off when the seed is ripe. 



4. SCAR, (hilnm) is the point by which the seed is 

 attached to the vessel or receptacle. 



Observation. At this point all the parts of the seed are connect- 

 ed ; through this part it is nourished while connected with its par- 

 ent plant ; and through it also, it imbibes the juices of the earth 

 previous to germination. 



Appendages to the seed. 



1. PAPPUS, (pappus.} PI. 16, fig. 5, c. The feathe- 

 ry crown of seeds calculated to wait them in the wind. 

 Ex. Dandeijon, Thistle. 



2. STJPK, (stipes) b. A thread which connects the 

 pappus with the seed. 



