262 DECOMPOSITE ORGANS. CHAP. I. 



In the former case he must frequently inspect the 

 Onion bed about the time the plants are coming 

 up ; and in the latter case he has only to take up a 

 little of the mud near one of the plants of Alisma 

 in the spring, and keep it moist with water in a 

 flower-pot, and the self-sown seeds will soon begin 

 to sprout ; or the seeds may be gathered when 

 ripe, and kept to be sown on purpose in the spring. 

 Cotyle- As there are some seeds whose cotyledon consists 



sible into" ^ one ^^ e on ty? ^ a ^ m g short of the general num- 

 several ^^ so there are also a few whose cotyledon is divi- 

 sible into several lobes, exceeding the general num- 

 ber. They have been denominated polycotyledo- 

 nous seeds, and are exemplified in the case of Lepi- 

 dmm sativum or common Garden Cress, in which 

 the lobes are six in number ; as in that also of the 

 different species of the genus Pinus, in which they 

 vary from three to twelve. In the former case 

 they are circular in their vegetating state ; and in 

 the latter they are lanceolate, originating in a whirl. 

 The Mosses, as it appears from the observations of 

 Hedwig,* should perhaps be referred to this divi- 

 sion also ; the lobes of the cotyledon being in 

 them numerous beyond all other examples, though 

 the propriety of this arrangement will depend 

 entirely upon the particular view that is taken of 

 the subject, as relative to the seed only, or to the 

 evolved plant. For the classes that are pure in 

 carpology, are not always pure in phy tology ; ^ a 

 * Fund. Hist. Nat. Muse, part ii. 25. f De Sem. vol. ii. 



