BENNETTITEAE 571 



various constituent organs of the fruit, and consider 

 their structure a little more in detail. 



The receptacle forms, as we have seen, the enlarged 

 termination of the axis of the fruit. The peduncle 

 has a structure like that of the stem, on a small scale, 

 and the bundles given off to the bracts divide up like 

 those of the vegetative leaves, though only to a small 

 extent. A remarkable feature in the anatomy of the 

 peduncle is the great development of the phloem, 

 which much exceeds the wood in thickness. This 

 peculiarity, which recurs in some of the American 

 species, may be explained by the great demands on 

 the organic food-supply made by the crowded repro- 

 ductive organs, and especially by the seeds/ The 

 receptacle itself is poorly preserved, but shows here 

 and there sections of collateral vascular bundles, on 

 their way out to the appendages. 



The bracts have, on the whole, the structure of 

 reduced foliage-leaves. Their outer surface is clothed 

 by ramenta, and stomata have been detected in their 

 epidermis. 1 Towards the inner surface of the bract, 

 the mesophyll has a fibrous structure, but the bulk of 

 the parenchyma is formed of short cells with a curious 

 scalariform thickening on their walls. Several large 

 gum-canals traverse the bract, which in this species 

 usually contains three vascular bundles. These bundles 

 are reduced in structure, but near the base, where they 

 are best developed, they seem to be of the mesarch 

 type usual in the foliar bundles of Cycads. 



The seed-pedicels, which are seen in great numbers 

 in the transverse section of the fruit (see Fig. 204), 



1 C. A. Harber, in MS. 



