120 SEEDS. 



(61) Colchicum Seeds. 



The seeds of Colchicum autumnale, Linn. (N.O. Liliacop). 



The seed-coat of colchicum seeds is composed of three layers 

 all of which are brown in colour. 



The outer layer (te) is the most deeply coloured, and consists 

 of elongated cells which, in surface view, are seen to be rather 

 large, and possess thick, brown, slightly wavy walls. 



The middle layer (tm) is paler in colour, and consists of 

 similar cells which, however, have thinner walls than those o 

 the preceding layer. 



The inner layer (ti) is made up of much smaller and more 

 regular polygonal cells. 



The thickening that is observable near the hilum of the seed 

 is composed of thin- walled, polygonal, isodiametric cells (ep) 

 characterised by the fact that they are filled with starch grains. 

 The latter are convex on one side and concave or angular on 

 the other ; they often exhibit a small stellate hilum. 



The horny endosperm consists of polygonal cells with very 

 thick, pitted walls ; they contain granular albuminoid substances 

 and fixed oil. 



The diagnostic characters of colchicum seeds are : 



(a) TJie large cells of the epidermis of the seed-coat with 

 rather thick, brown ivalls. 



(b) The cells of th endosperm -with thick, pitted walls. 



(c) The thin-walled cells of the thickening near the hilum 

 filled with small starch grains. 



