MONOCOTYLEDONS^. 35 



is considered the true cotyledon by some authors ; 

 while others deem the former the true one, in order to 

 be consistent with the characteristic title of the class. 

 Be this as it may, it is certain neither do the imputed 

 office of cotyledons ; that being" performed by the 

 albumen, which yields the nourishment necessary for 

 the young plant till the radicles have established 

 themselves in the soil. 



The corculum, that is, the body whence the roots 

 and stem originate, is a compound organ, consisting 

 of the rudiments of many sets of roots, and of many 

 culms. Each joint of the culms is constituted like 

 the corculum, i. e., it is capable of producing both 

 roots and new sets of shoots, if placed in favouring 

 circumstances. Whether a single grain (of wheat 

 for instance) throws up one or ten culms, depends 

 entirely on the fertility of the soil, favourable season, 

 or space allowed it to grow in ; consequently, the 

 wheat plant is capable of repeated division and sub- 

 division by art to any extent during the spring 

 months ; showing that the corculum is an aggre- 

 gation of vital essences which are developed either 

 singly or collectively. 



The following figures are illustrative of the fore- 

 going description, and may be considered as types of 

 the germination and constitution of the Graminece 

 in general, whether annual or perennial. 



D 2 



