134 



HARDWICKE'S SCIENCE-GOSSIP. 



It is in habit and growth like Pteris, simply pinnate 

 with pinnae from four to ten inches long, and the 

 general aspect straggling. 



L. flabellulata, Dry., has little half-round pinnae 

 ranged up both sides of the stalk, which is occasion- 

 ally eight or ten inches in height. 



L. heterophylla, Dry., is bipinnate, that is the 

 pinnre are pinnate again, and these secondary 

 divisions are either half round or pointed. This 

 species may be said to be a combination of the other 

 two. 



Lindsasa may be distinguished from Adiantum as 

 the fructification is continuous and not in patches. 

 Ensifolia moans sword-shaped ; heterophylla, ir- 

 regular-leaved ; flabellulata, like a fan. 



Gen. VI. Adiantum, Linn. 

 (Maiden-hair.) 



Who does not know a maiden-hair fern, so called 

 from the black delicate stalk peculiar to every 

 member of the family? The well-known form, 

 however, is not found among the commonest species 

 in the island. The name " Adiantum " was given to 

 the fern by Pliny, and means "not to be wetted," 

 from the faculty the leaves have of throwing off the 

 drops of water, under which they love to grow. 



Three species are named by Dr. Hance as found in 

 the island. 



A. luniilaliiin, Burn, (moon-shaped maiden-hair), 

 is more often met with on the mainland. It is a very 

 delicate fragile fern, so that specimens required for 

 the herbarium must be shut up in a book or paper as 

 soon as gathered. 



A. caudatum, Hook., is common. Like the 

 preceding, simply pinnate, but quite unlike in form 

 and texture. The little pinnae on each side of the 

 stalk are rough, hairy, close together and deeply 

 jagged, each jag bearing the sorus. 



A.flabdlulatum, Linn., is the most universal of the 

 three. The divisions of the frond are in the form of 

 a fan, and in twos, each pair nearly starting from a 

 common centre. The venation is also fan-shaped. 



The sori of Adiantum are too well known to need 

 description. They are in patches along the margin. 



The young frond is often tinged red or purple. 

 This is also the case with Blechnu/n oricntale (hard 

 fern). 



(To be continued.) 



Hybernation of Cuckoo.— I cannot find any 

 allusion to the hybernation of cuckoos, either in 

 White's "Selborne," or in Buckland's Notes to the 

 same, although White has so much to say about the 

 hybernation of swallows. He mentions that when the 

 thermometer is above 50 , bats fly abroad in any 

 month of the year. — M. E. Pote. 



THE ASCENT OF RORAIMA. 



THE successful expedition of Mr. im Thurn to this 

 remarkable mountain last December has excited 

 a good deal of interest, from the difficulties attending 

 the ascent, and the consequent ignorance which has 

 prevailed concerning the nature of the summit. It 

 was natural to expect, from the inaccessibility of the 

 plateau, that when once it was reached, valuable 

 information would be obtained as to the fauna 

 and flora, if there were any, which had been for so 

 long a time somewhat secluded from the surrounding 

 country. In " Nature" for April 30th, extracts are 

 given from a paper lately read at the Royal 

 Geographical Society by Mr. J. H. Perkin, who 

 accompanied Mr. im Thurn. From these it appears 

 that on the 2nd of December the explorers reached a 

 group of houses about four miles from Roraima, 

 which is near the border of British Guiana, and three 

 from Kukenam, these flat-topped mountains with 

 dark precipitous cliffs, seeming like huge fortresses 

 built on a mountain-top 7000 feet high, and with 

 walls 1200 to 1800 feet in height. The features of 

 these mountains, as seen from a little distance, seem 

 to be extremely grand. Clouds of white mist 

 accumulate in the gorge between, and, as the day 

 advances, rise towards the summits, as was the case 

 on Roraima soon after the top was reached, whereby 

 a limit was put to the wanderings of the explorers ; 

 while after wet weather the water pours over the 

 edge in splendid falls, some having a clear leap of 

 1500 feet down. The scantiness of the vegetation 

 found on the exposed top of Roraima is attributed to 

 the earth being thus washed away from the surface. 

 On the sloping sides of the mountain, before reaching 

 the cliffs, a large piece of swampy ground was met 

 with, which produced exquisite orchids and ferns, 

 and also the Utricularia Humboldtii and the Heliam- 

 phora or pitcher-plant with cup-shaped leaves full of 

 water. Another Utricularia was re-discovered higher 

 up, a small plant, two or three inches in height, 

 growing on the branches of trees, and having a large 

 deep crimson blossom. Higher still was a quantity 

 of a species of heath with dark pink blossoms of six 

 petals, about the size of a halfpenny. As the 

 travellers reached the top of the ledge by which they 

 made their way up, a number of fantastic weird- 

 looking rocks were seen, but no trees. Small bushes 

 from three to six feet high, a few orchids, two species 

 of thick-leaved ferns, and a Utricularia, formed all 

 the vegetation seen upon the summit. The rock was 

 found by Mr. Perkin to be too hard to permit of his 

 cutting it. The height attained was reckoned, by 

 boiling the thermometer, to be ,8600 feet. The 

 ascent to the summit was made on December iSth. 

 "Nature" publishes also illustrations of the scenery 

 of Roraima taken by Mr. im Thurn, from whom a 

 more detailed report is expected. 



