S30 



REPRODUCTION IN 



decomposition of carbonic acid, and the fixation of carbon by the 

 plant (344 — 350) ; while germination is necessarily attended by an 

 opposite transformation, namely, the destruction of a portion of or- 

 ganized matter, with the evolution of carbonic acid.* In germina- 

 tion, as in any other act in which matter is transformed or trans- 

 ferred, there is a certain expenditure of force and loss of organized 

 material. The plantlet is obliged to decompose and destroy a part 

 of the starch or other material provided for its initial growth, in 

 order that it may transform the rest into dextrine and sugar, and 

 this again into cellulose or the material of the new cells formed in 

 its growth. 



650. The study of the seed, and of the development of the em- 

 bryo it contains into a plantlet, completes the cycle of vegetable life 

 in the higher grade of Pha3nogamous plants, and brings us back to 

 our starting-point (118, 119). 



CHAPTER XII. 



OP EEPEODUCTION IN CRYPTOGAMOUS OR PLOWERLESS PLANTS. 



G51. The lower grade of Crtptogamous ok Flowerless 

 Plants (Chap. II. Sect. I.) would now require, to be considered, 

 both as to the vegetation and their reproduction. But the plan of 

 structure in each principal Cryptogamous family is so peculiar, 

 and the organs of fructification especially so diverse, that their 

 morphology cannot be presented under one common type, as in Phos- 

 nogamous vegetation. Each great family or group would have to 

 be separately treated, and with much fulness of illustration, to make 



* Seeds may casually germinate while attached to the parent plant, especially 

 such as are surrounded with pulp, lil;e those of the Cucumber and Jlclon. The 

 process is liable to commence in wheat and other grain, when protracted warm 

 and rainy weather occurs at the period of ripening ; and the albumen becomes 

 glutinous and sweet, from the partial transformation of the starch into dextrine 

 and sugar. In the Mangrove, which forms dense thickets along tropical coasts, 

 germination habitually commences in the pericarp while the fruit remains on the 

 tree ; and the radicle, piercing the integuments which enclose it, elongates in the 

 air ; such a plant being, as it were, viviparous. 



