PLATE III. DESCRIPTION OF FIGURES. 



I. Vertical-longitudinal section of nectar gland from petiole of EvAnus communis 



(x8). 



II. Vertical transverse section of the same near the distal end of the true gland 

 (x8). 



III. A portion of I, more highly magnified (x 100). 



IV. Vertical transverse section of gland from mid-rib of a leaf of Gossypinm herba- 



oewm (x 17). 



V. A portion of IV, more highly magnified (x 100). 

 VI. Flower cluster of Marcgravia nepenthoides, reduced. 

 VII. Involucrate cluster of flowers of Poinsettia pulcko-rima, in the staminate state, 



natural size. 



VIII. The same at an earlier period, while in the pistillate state. 

 IX. Vertical section of a cluster in which the pistil is abortive, in the staminate 



state, natural size. 

 X. The same, entire. 



XI. Double petiolar gland of Bicinus communis, seen from above, natural size. 

 XII. The same, from the side. 

 XIII. Double involucre of Gossypium lierbaceum, natural size, one of the bracts of the 



inner wheel. 



In all of the figures, a indicates the adenophore ; e, the epidermis ; /, the fibro vas- 

 cular bundle; g, the gland proper; I, the lamina of the leaf; o, the ovary; p, the 

 petiole. 

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