A STUDY OF CERTAIN FOLIACEOUS 

 COTYLEDONS 



By Francis Ramaley 



Introductory. — Little attention has been given by botanists to coty- 

 ledon structure. In the standard works of reference I have found 

 nothing on the subject. Every botanist knows the appearance of the 

 cotyledons of the pea, bean, morning glory, and castor oil plant but I 

 think that few have examined cotyledons microscopically. As is well 

 known, the cotyledons of a plant are seldom of the same shape as the 

 leaves. Occasionally they are of similar shape but this is in cases where 

 the leaves are of simple form, as ovate or oblong. Even in these cases 

 the venation of the cotyledon is nearly always different from that of the 

 leaf. If then the cotyledon and leaf be different in gross structure it 

 will be of interest to compare the internal anatomy. 



Scope of the paper. — The present paper is intended as a very small 

 contribution to the subject. It is a record of observations on a few 

 plants with foliaceous cotyledons. A "foliaceous" cotyledon is not 

 necessarily a cotyledon resembling the leaf of the species but one which 

 is thin and which looks externally as if it were a leaf. In the following 

 pages are given detailed accounts of the species examined. The sepa- 

 rate accounts are all arranged in the same way so that comparison is easy. 

 I have thought it best to illustrate everything with diagrams and figures 

 because, as cotyledon structure is generally unfamiliar, inaccurate 

 conclusions might be drawn if only a few figures were given. When 

 making drawings of the epidermis I have chosen parts of the leaf surface 

 which would show the typical structure and have avoided portions in 

 the vicinity of the large vascular bundles or near the leaf margin. My 

 drawings of leaf cross sections are slightly diagrammatic. 



Material. — The plants were grown at the royal Botanical Garden, 

 Peradeniya, Ceylon during the months April to July, 1904. I wish to 

 express my appreciation of the facilities offered me for study at Pera- 

 deniya and to thank Mr. J. C. Willis, ihe director, and Mr. J. B. 



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