96 CYCADACEAE 



occur two or three layers of hard and tough sclerenchyma, 

 which forms a continuous mantle on the upper side of the 

 leaf, but occurs in longitudinal strands only on the under 

 side. In the furrows between the strands are the stomata, 

 deeply sunk into the epidermal tissue. (Fig. 62, Nos. 8 and 9.) 



The pollination of some species of S. A. Cycadaceae 

 is effected by insects. Miss Alice Pegler has devoted 

 much time to this question, by observing Encephalartos 

 Alte7iste'mii and E. villosus at their natural habitat near 

 Kentani in the Transkei. Her first collection of insects 

 consisted entirely of a certain weevil mentioned by 

 Pearson, viz. Phlocophagus hispidus, but as this had been 

 found only on the male plants, it might have been merely 

 feeding on the pollen without visiting the female cones. 

 Later on, however, Miss Pegler sent us some other col- 

 lections of insects, among which we found two kinds of 

 beetles, taken on the female as well as the male cones 

 (see Plate 15; Fig. 9). One of these is also a weevil, viz. 

 Derelomus langiiidus* '. As the insects from the female cone 

 carried some pollen grains of E?icephalartos the entomo- 

 philous nature of the genus can hardly be doubted. 



Similar observations have been recently made by 

 Dr Rattray in the neighbourhood of East London, who 

 states that the male cones of E. villosus, when fully developed 

 and ready to shed their pollen, emit a powerful, nauseous 

 odour and are visited by swarms of a certain weevil t. (May.) 



The seeds are often infested with a weevil [Antliarhinus 

 Zamiae), which is occasionally so numerous that the entire 

 kernel of the seed is consumed, a small puncture in the 

 shell indicating where the introduction of the eggs had 

 taken place. (Plate 15.) 



Plants with cycadaceous characters were predominant 

 in mesozoic times, but at present the family consists only 

 of 9 genera with a total of 100 species. Two genera 

 with 9 or 10 species occur in S. A. (See page 90.) 



* Kindly identified by Dr L. P£ringuey, Director S. A. Museum, Capetown. 

 j- Named PhloeophagUi but obviously Antliarhinus. See page 263. 



