g (il.'ACK K. COOI.KV OX 



well-ni"-h so. These j)liints are P((ris qi((i(lrifoIi((, 7'ri/Iiutii, ovntnm, and f'oJchicirni 

 autumnale. The deep brown color, which, everywliere else in these endosperm cells, 

 resnlts from the iodine liirnished, varies in shade to dull gray-hrown, as in seeds of 

 Allium ursinum, l)ut clear red-brown is the general rule. 



If iodine is supijlied to the reserve cellulose in very small (luantities, particularly if 

 alcoholic solutions are weakened with water, or a crystal of iodine is dissolved with water 

 on the slide, the cell walls are not uniform in their behavior in the different seeds. 



Some are blue, or violet with tendencies to dirty brown; others are clear yellow or 

 yellow-brown, with no tinge of violet or blue. 



Asjxtrdf/iis offichuilis, Hostu caerulea, Oni'dhogalum cmidatum, Narcissus ^^ncmc^o- 

 narcissus, and Lilinm martagon are yellow or yellow-brown with no tendency to violet or 

 blue; this is also the case with Allimn (-qxi, \^\i\\i^ A. nrslnum is pale violet to dirty 

 brown. All the other seeds show in their reserve a trace of violet or blue, when weak, 

 watery solutions of iodine ai'e applied. 



In Scilla siblrlca the color is often a clear beautiful blue, but it varies somewhat in 

 different seeds. 



To summarize: we notice the following reactions with iodine solutions. 



1. With strong potassium iodide solutions. 



a. (The exceptions.) Nearly colorless. Examples. Colchicum autumnale. 



Paris quadrifolia. 

 Trillium ovatum. 



b. (The rule.) Deep brown-red to gray-brown. Exs. Polygonatum multiflorum. 



Iris pseudacorus. 

 Lilinm martagon. 

 Lloydia serotina. 

 Galtonia candicans, etc. 



2. With weak watery solutions from a crystal of iodine, or alcoholic solutions weak- 

 ened with water. 



a. Yellow, or yellow-brown. Exs. Asparagus ollicinalis. 



Ornithogahun caudatum. 

 Hosta caerulea. 

 Narcissus pseudo-narcissus. 

 Lilinm martagon. 

 Allium cej)a. 



