IOWA ACADEMY OF SCIENCES. 



199 



COMPARATIVE ANATOMY OF THE CORN CARYOPSIS. 



L. H. PAMMEL. 



The fruit, or what is popularly known as the seed, of corn 

 has been studied by a number of investigators, asHarzS Hunt% 

 Goodale% Hackel% Jumelle', True^ and Blyth'. The litera- 

 ture on the structure of the corn caryosis is quite large; many 

 of the works on foods discuss the subject. 



The outer part of the so-called seed 

 is the wall of the ovary. It begins 

 with a greatly thickened epidermis 

 (a); this is followed by a variable 

 number of rows of thick -walled cells 

 provided with pore canals. The wall 

 of the ovary is frequently differenti- 

 ated into several layers, usually two, 

 and a third more difficult to make 

 out, the inner part being less thick- 

 ened than the outer. This layer 

 contains some of the pigment in the 

 colored varieties. The cells contain 

 only small amounts of protein matter. 

 The cell-walls are greatly thickened. 

 The wall of the ovary closely joins 

 the testa of the seed. But one coat 

 remains in the mature seed, the inner, 

 the outer being absorbed in develop- 

 ment. The testa is insignificant since 

 the protective features are supplied by the thickened wall 

 of the ovary. The cells are elongated, thin-walled, and 



1 Harz Landwirthschaftliche Samenkunde. 8 :1235. 



2 Hunt, F. L. A kerael of [adiaa corn. Prairie fl'd.rnnr. 58: 198. Thirteentii R ipt. 

 Board of Trustees of Uaiv of 111. 19o. 1886 



3 Goodale, G. L. Physiological botany. 181. 



4 Hackel, Edward Tin true grasses. 24-25. (Eng. tr.ins. by F. Lamson-Scribner 

 and Effle A. Southworth ) 



5 Jumalle. Sur la constitution du fruit d. graminees. Soc. d. 9ci. Nancy. Seanc. 

 23 Juillet, 1888. (According to Knoblaucli. Just Bot. Jahresb. 16: (5) 1888.) 



6 True. On the development of the caryopsis. Bot. Giz. 18:214. pi. 24-26. f. 10. 



7 Blyth. Foods, their composition and uses. 216. (4th ed.) 



Fig. 5 

 Flint corn, a, epidermis; c. cap- 

 sule and testa; d, aleurone layer 

 8, starch cells 



