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, asHarz^ Hunt% 

 Goodale^ HackeP, 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, 



Fig. 5 

 FUnt corn, a, epidermis; c. f H,p- 



suie and testa; «, aieuione layer; ^\^q 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. 2:1335. 



3 Hunt, F. L. A kerael of Cndiiia cora. Prairie ti'd.rmjr. 58: 196. Thirteenth R ?pt» 

 Board of Trustees of Univ of 111. 198. 1886 



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



4 Hackel, Edward Th ) true grasses. 24-35. (Eng. tr.ins. by F. Lamson-Scribner 

 and Effle A. Southworth ) 



5 Jumelle. Sur la constitution du fruit d. graminees. Soc. d. Sci. Nancy. Seanc. 

 23 Juillet. 1888. (According to Knoblauch. Just But. .lahresb. 1 (J : (5) 1888.) 



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



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



