204 



IOWA ACADEMY OF SCIENCES. 



HISTOLOGY OF THE CORN LEAP. 



4 



ROBERT COMBS. 



The stem bears lateral organs, the 

 leaves. These occur at definite points, 

 the nodes, and originate in an exogene- 

 ous manner. The leaf arises in the form 

 of a papilla and is not covered by the 

 superficial tissue as the root is. The 

 mature leaf is divided into two parts, the 

 blade and the sheath. At the base of 

 the blade occurs the membranaceous 

 ligule. The veins of the leaf are par- 

 allel and are continuous with those of 

 the sheath. The vascular bundles of the 

 sheath connect with those of the stem. 

 The function of the leaf is the prepara- 

 tion of food by a process known as pho- 

 tosynthesis. This same function is also 

 shared by the sheath and stem, but not 

 in nearly so marked a degree. 



Holm, Theodore. A study of some anatomical char- 

 acters of North Amerlci Gramlneae. I. Bot. Gaz. 111111111111 

 16: 166-171.PZ. 15. II. 16: 219-325, pi. 21-22. III. 16: 275- 

 281, pi. 23-24. IV. 17: 358-3 2. pi ?i. V. 30: 362-365, pi. 

 26 VI. 21: 357-360, pi. 27-2S. VII 2 '2 : 403-403, pi m 

 - Slrrlne, Emma, and Pammel, Emma. Some an4,to- 

 mlcal studies of the leaves of Sporobolus and Panlcum. 

 Proc. la \cad. Scl. 3:148-159, pi. 6. 1895 (Contrib. 

 Bot. Depart. la. State Coll. Agric and Mech Arts, 

 1: 148-159, pi. a.) (Bibliography of this subject may be 

 fouad in this paper.) 



Slrrlne, Emma. A study of the leaf anatomy of 

 some species of the genus Bromus Proc la. A.cad. Sci. ^^S- H- 



4: 119-135 pi. 4-8. (Contrib Bot. Depart. la. State Ooll. Leaf of corn showing 

 Agric. and M«ch. Arts, 4:ill9-125, pi. J-S.) sheath, ligule, and blaii 



PaminQl, Emma. A co npiratlve study of the leives of Lolium, Festuca, and Bro- 

 mus. Proc. la. Acad. Sci. t: Ii6-Ul. p'- SJ-U. (Ooatrlb. Bot. Depart. la. Soate Ooll. 

 Agric. and Mech. Arts, 4: 125-131, pi 0-11) 



Weaver, 0. B An anatomical study of the leaves of some species of the genus 

 Andropogjn. Pro3 la. Acad. Scl 4.:\^Z-Vihpl.l2-lo. (Oontrib. Bot. Depart la. State Ooll. 

 Agric. and Mech Arts, 4: 132-137, 2^1. 12-15.) 



Bill, Oarleton R An anat)mi;al study of the leaves of Eragrojtis. Proc. la. 

 Acid. Sci 4: IW-U-i, p\. IH-IS (Oontrib. B)t D3part. la. State Ooll. Agric. and Mech. 

 Arts, 4: 138-145, pi 16 18 ) 



Ogden, Miss E. L. L3af structure of Jouveaaadof Eragrostis obtusifolia. Bull. 

 Div. Agrost. U. S. Depart. Agric. 8: 12-30. pi 8-9.) 



