iJ4y JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



Museum, South Kensington, there is a large trunk from the 

 coal measures near Edinburgh. It was nearly 50 feet in 

 length when I saw it in the quarry, but only about 20 feet of 

 it were sufficiently entire to be erected in the grounds of the 

 museum. It is feet in diameter. The whole length in the 

 quarry was the undivided trunk below the first branches. It 

 is in such a good state of preservation that the coniferous struc- 

 ture is easily identified. Coniferse are found all through the 

 subsequent rocks, gradually showing the incoming of living 

 genera. In the Secondary rocks numerous examples of Cycadese 

 occur, beginning in the Lias with a trunk showing the charac- 

 ters of C}'cas. In the Wealden are fruits like those of Zamia, 

 and throughout the Upper Secondary strata are found the remains 

 of an extinct group of Cycadese, to which the " Crows' nests " of 

 Portland belong ; they had fleshy fruits analogous to those of the 

 Yew. Araucaria appears in the Lower Oolites ; Pinus in the Upper 

 Oolites ; Abies, Cedrus, and Sequoia in the Cretaceous rocks ; 

 Callitris and other genera in the Tertiaries. 



At present the Cycadese are chiefly confined to tropical 

 regions, although some pass southwards — in Australia (Macro- 

 zamia), in Africa (Encephalartos and Stangeria) ; northwards in 

 Japan (Cycas revoluta), and in the United States several species of 

 Zamia. The species of Cycas are found in the countries and 

 islands bordering the Indian Ocean, the headquarters being in 

 the Malayan Archipelago, extending northwards through the 

 Philippine Islands to Japan, westwards to India and Ceylon, 

 southwards to the Comoro Islands, and perhaps Madagascar on 

 the west, and to tropical Australia on the east. The fruit is borne 

 on the edges of altered leaves which grow in the same series 

 as the ordinary leaves, and when they fall ofT a lozenge-shaped 

 scar is left, like to, but smaller, than that of the ordinary leaf. 

 Cycas is the first known, and the best known, of the whole order, 

 though new species are being continually added to the genera. 

 The fruits in the other genera are borne in cones. In Zamia the 

 seeds are produced on the inner surface of peltate, not imbricate 

 scales, which are arranged in a linear series. Zamia, with the 

 closely allied Ceratozamia, is found in the tropical regions of 

 the New World, extending northwards into Florida and south- 

 ward to Bolivia. 



In the Old "World we find Cycads more closely related to 



