2 TRANSACTIONS AND PllOGEEDlNGS OF THE, [Sess. lxv. 



New Zealand, there is no part of it whicli displays such au 

 extraordinary wealth of fern life. It would be impossible 

 to deal in a paper like this with the whole subject of the 

 Ferns of Jamaica — the number of species, and even of 

 genera, being so great, as we shall presently see. It will 

 be better to confine its limits mainly to the fascinating 

 group of Filmy Ferns represented by the genera Hymeno- 

 'phyllum and Trichomancs, merely adding some observations 

 on one or two of the more remarkable forms that occur 

 outside of these genera. 



It will be necessary, first, to say something in regard to 

 the physical features of the island itself, by way of explan- 

 ation of the fact that ferns of all kinds find there a home 

 so well adapted to their nature and requirements. 



Jamaica, then, is a hilly or, rather, mountainous island. 

 There is very little level ground, even along the seacoast. 

 Everywhere the land begins to rise almost at once, 

 gradually ascending to the heights of the central chain 

 of hills, which, in the Bhie Mountains, attain an elevation 

 of more than 7000 ft. There is thus great variety of 

 temperature and climate. In the lowlands, the mean 

 temperature is about 75° at night, and about 85° during 

 the day, but the heat is tempered by both land and sea 

 breezes. At Newcastle (3800 ft.), the mean temperature 

 of the hottest month (July) is 68°, and of the coolest 

 month (January) 61°. As you ascend still higher the 

 mean temperature, of course, proportionately falls, till you 

 gain the summit of the Blue Mountains, where frost has 

 been occasionally, but rarely, registered. A large part 

 of the surface of the island is therefore free from the 

 excessive tropical heat under which the great majority of 

 ferns cannot luxuriate. But ferns demand something else 

 than moderately cool temperature, they must have both 

 shade and moisture. Shade they receive in abundance 

 from the bush or scrub — one can hardly call it forest — 

 that clothes the hillsides, and is generally dense enough to 

 screen them from the direct rays of the sun. There is no 

 lack of moisture either. Streams everywhere run down 

 from the upper regions to the sea, more than one hundred 

 of them in all. Then from these streams, and from the 

 ocean, the heat of the sun raises copious vapours, which 



