54 



is about a quarter of an inch in length and scaly rather than 

 fleshy. The plumule is lodged at the same level as this coty- 

 ledon. Further elongation of a cylindrical structure removes 

 the cotyledon and plumule from the proximity to the beak. 

 It attains a maximum length of about nine inches. It is groo- 

 ved length w^ise on the side v^^hich is in a line with the inser- 

 tion of the scaly cotyledon. This grooved structure is in fact 

 a petiole, belonging to the other cotyledon. This cotyledon 

 forms the bulk of the contents of the seed. It exactly fits into 

 and fills up the seed cavity. The seed has only one soft brown 

 cover viz. the testa. The other coat, tegmen, is absent. The 

 bulky cotoledon never leaves the seedcoat nor the shell (pericarp). 

 It supplies material for the grow^th of the plant until its apex 

 nears the waterlevel and develops chlorophyl within its leaves. 

 This process of absorption from the reserve material within 

 the seed extends over two or three months. 



The main root and hypocotyl cannot be distinguished from 

 each other at any stage. The whole length from insertion of 

 the cotyledons to the tip of the radicle bears lateral non- 

 branching negotively geotropic roots. Their orientation is 

 peculiar in that they cover only one side of the main root. 

 The main root does not elongate more than a couple of inches. 

 By the time it has developed sideroots there appear several 

 adventitious roots at the level of the insertion of the coty- 

 ledons. These are also, like the other roots, negatively geotropic. 

 They may be simple or sparingly branching. They are thread- 

 like and white or blue in colour. Besides, there also appears 

 a smaller number (generally four) of the pectinate bodies from 

 the same level. 



The leaves on the primary shoot are ribbonlike at first. 

 Subsequent leaves are spatulate. They do not bear any float. 

 The floats do not appear until the plant reaches the water- 

 surface, which may involve growth of over ten feet in length. 



The plate illustrates two seedlings of a spineless variety from 

 the Central Provinces which were grown at the Ganeshkhind 

 Botanical Gardens, Kirkee, for scientific study. 



