204 



IOWA ACADEMY OF SCIENCES. 



HISTOLOGY OF THE CORN LEAF. 



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 a.nd 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. 1 1 njnj 



Holm, Theodore. A. study of some anatomical char- 

 af^ters of North Amerlc i GraminecB. I. Bot. Gaz. I lilllllll'll 



16: 166-171.pl. i5. II. 16: 219-325, pi. 21-22. IH. 16:275- 

 2^1, pi. 23-24. IV. 17: 3.58-3 2, pi 21. V. 20: 362-365, pL 

 26 VI. 31: 357-360, pi. 2;-3S. Vtl 2 '2 : 403-40 i, pi 20. 



Sirrine. Eaama, and Pammel, Emma. Some anato- 

 mical studies of the leaves of Sporobolus and Panlcum. 

 Proc. la A.cad. Sci. 3: 148-159. pi. 6. 1895 (Contrib. 

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

 1: 148-159, pi. 6.) (Bibliography of this subject may be 

 found in this paper.) 



Strrine, Emma. A study of the leaf anatomy of 

 some species of the genus Bromus Proc la. Acad. Sci. F'S- H- 



-1: 119-125 pi. 4-S. (Contrib Bot. Depart. la. State Coll. Leaf of corn showing 

 Agric and Mpch. Arts, 4:'119-125, pi. 4-S.) sheath, ligule, and b.aie 



Pammel, Emma. A co up irative study of the leaves of Lolium, Pestuca. and Bro- 

 mus. Proc. la. Acal Sci. t: 136-lU, p' f)-ll. ( Joatrlb. Bot. Depart. la State Coll. 

 Agric. and Mech. Arts, -4: 121-131, pi 9-11 ) 



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

 Andropogon. Proc la. Acad. Sci 4: 132-137. pi. 12-1.3. (Oontrib. Bot. Depart la. State Ooll. 

 Agric. and Mech Arts, 4: 132-137, pi. 12-15.) 



Ball, Oarleton R An anat)mi:al study of the leaves of Eragro5tls. Proc. la. 

 Acad. Sol 4: 138-145, pi. Ifi-lS (Ooatrib. Bit Depart. la. State Ooll. Agric. aad Mech. 

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



Ogden, Miss E. L. L^af structure of Jouvea aid of Eragrostls obtuslfolla. Bull. 

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



