OCTOBEK 2, 1885.] 



SCIENCE, 



297 



stiff hairs, all pointing downward. The lower third 

 of the interior is lined with slender bristles, the mid- 

 dle third is perfectly smooth, and the upper part is 

 lined with hairs similar to those in the hood. But 

 still the pitcher is open to the rain, secretes little or 

 no honey, and absorbs the juices of the captured in- 

 sects in the form of a liquid manure only. 



Sarracenia flava shows a marked difference from 

 the preceding, in that it secretes a nectar just below 

 the hood. In Sarracenia variolaris (fig. 3), there is 

 a wonderful advance. The hood bends over the 

 orifice, thus shutting out the rain: it is marked on 

 its posterior portion with white, translucent spots, 

 and reticulations where honey is secreted ; a secretion 

 is formed at the bottom of the pitcher, which has 

 the peculiar property of asphyxiating its victims: 

 and a yet more striking advance is found 

 to be a honey-baited pathway running 

 from the ground up along the wing of the 



w 



Fig. 3. 



Fig. 4. 



leaf to the hood, and a short way into the orifice. 

 A still further advance is found in Darlingtonia, a 

 genus native to California. The hood forms a 

 vaulted arch, mottled with spots and reticulations. 

 The only entrance to the leaf is from below; and 

 on each side of this entrance is a long appendage, 

 the whole likened to a fish-tail (fig. 4). The inside 

 of this secretes honey, and is covered with hairs. 

 On the outside, running along the wing from the 

 ground to the orifice, is a pathway of nectar which 

 lures creeping insects to destruction, while the wings 

 attract flying ones. A fluid secretion in the bottom 

 of the cup has the power of decomposing the insects. 

 The flowers of these plants are also peculiarly mod- 

 ified for cross-f ertilization ; and the greatest amount 

 of advance is found in the highest developed genus 

 Darlingtonia, where the change has kept pace with 

 the evolving leaves. 



INSULAR FLORAS. 



It is a large quarto volume which we have 

 before us, dealing with the botany of sundry 

 small islands which were visited by the Chal- 



RepoH of the scientific results of the voyage of H. M.S. Chal- 

 lenger, during the years 187.3-76. Botany, vol. i. London, 

 Go'cernraent, 1885. 4°. 



lenger in her scientific cruise, made up of four 

 reports, separately paged, and three indexes, 

 and illustrated by sixty-five plates, w^hich are 

 consecutively numbered. With some arith- 

 metical pains we ascertain that the letter-press 

 occupies about 1,080 pages, counting in the 

 leaves, one for each plate, upon which the fig- 

 ures are explained. A second volume is to 

 contain the pelagic botany of the expedition. 

 This one, under Mr. Hemsley's authorship, and 

 devoted to the botany of the land and shores, 

 concerns itself with the islands onh^, the con- 

 tinental collections of the cruise being too frag- 

 mentary, and of too well-known materials for 

 any advantageous enumeration. Insular bot- 

 any, however, has an interest of its own, — 

 an interest quite independent of the size of 

 the islands ; for the botan}' even of small 

 islands raises large and difficult questions. 

 Moreover, their botany needs the most prompt 

 attention ; for it is everj'where undergoing 

 rapid and irreparable deterioration and loss. 

 At least four St. Helena plants once known 

 to science have shared the fate of the dodo ; 

 several others are on the very eve of extinc- 

 tion ; and no one knows how many have per- 

 ished unknown and unconsecrated by scientific 

 baptism. We are told in this vohime that 

 on St. Helena, — 



'' In 1709 trees still abounded, and one, the native 

 ebony (Melhania melanoxylon), in such quantities 

 that it was used to burn lime with. In 1745, however, 

 the governor of the island reported to the court of 

 directors of the East-India company that the timber 

 was rapidly disappearing, and that the goats should 

 be destroyed for the preservation of the ebony, and 

 because the island was suffering from drought. He 

 was instructed not to destroy the goats, as they were 

 more valuable than ebony. Another century elapsed ; 

 and in 1810 another governor reports the total de- 

 struction of the great forests by the goats, which 

 greedily devour the young plants, and kill the old by 

 browsing on their leaves and bark; and that fuel was 

 so scarce that the government paid for coal (and this 

 in a tropical climate) £2,729 7s. 8d., annually. . . . 

 About this time the goats were killed; but another 

 enemy to the indigenous vegetation was at the same 

 time introduced, which has now rendered it certainly 

 impossible that the native plants [what are left of 

 them] will ever again resume their sway. Major- 

 Gen. Beatson proposed and carried out the introduc- 

 tion of exotic plants on a large scale," 



The result of which is, that a foreign vegeta- 

 tion, chiefl}' European, Australian, and South 

 African, of about sixt}' phenogamous species, 

 and most of them wortliless w^eeds, has taken 

 the place of the native flora, nearly all of which 

 was peculiar to the island, and which was 

 known to have covered it with luxuriant forests 

 down to the water's edoe. The existino- rem- 

 nant of this peculiar flora lingers, rather than 



