STRUCTURE.] FALSE STIPULES OF CUCURBITS. 807 



supposition the leaves of Cucurbits must be regarded as being 

 compound. Mr. Payer puts the case of Cucurbits thus : 

 " There are many plants in which nbro-vascular bundles are 

 detached at three different points of the circumference of the 

 cylinder constituting the medullary sheath, generally at one 

 and the same height, and at a little distance from the origin 

 of a leaf: these bundles traverse the herbaceous envelope, 

 and pass into the pulvinus (coussinet) of that leaf. There, 

 sometimes, all three enter the petiole, sometimes only one of 

 them, viz., that in the centre ; the two lateral ones continuing 

 the nervation of the two lateral stipules. Now if the lower 

 leaves of the cultivated melon be examined, no tendril will 

 be found to exist at their side ; it will be seen that the three 

 nbro-vascular bundles which separate from the medullary 

 sheath, ascend all three into the petiole, and that the bud 

 formed at their axil, and always placed between the inter- 

 mediary bundle and the stem, is decidedly at the middle of 

 the base of the leaf. If, on the contrary, the stem-leaves 

 which have a lateral tendril are considered, we observe that 

 of the three nbro-vascular bundles, only two, the central, 

 and one of the lateral ones, enter the petiole, and that the 

 other penetrates into the tendril. In this case, the bud, from 

 its constant position between the middle bundle and the 

 stem, is no longer, like this middle bundle, at the centre of 

 the base of the petiole, but on the side, and appears to be 

 almost between the leaf and the tendril. Lastly, we fre- 

 quently meet in botanical gardens with the upper leaves each 

 accompanied by two lateral tendrils. Anatomy then shows 

 that a single central bundle traverses the petiole, and that 

 the two lateral ones pass each into a tendril. With respect 

 to the bud, it necessarily is situated between the middle of 

 the base of the petiole and the stem." (Annals of Natural 

 History, xvi. 70.) 



Sometimes it is difficult to distinguish from true stipules 

 certain membranous expansions, or cilise, or glandular append- 

 ages of the margin of the base of the petiole, such as are 

 found in Crowfoots (Ranunculacese), Dogbanes (Apocynaceae), 

 Umbellifers, and many other plants. In these cases the real 

 nature of the parts is only to be collected from analogy, and 



