4 6 



NA TURE 



[July 8, 1922 



yard pest. Similarly many attractive flowers have 

 become in Madeira pernicious pests ; such are Oxalis, 

 Eupatorium, Scenecio, and Freezia refracta. 



Madeira could, however, be made a focus for the 

 dissemination of plants of economic value. The gourd, 

 Sechium Edule, has remarkable food value, and is very 

 potent in fat utilisation. The plant shows a singular 

 development of the seed-surrounding flesh into the 

 permanent stem growth of the climbing plant. During 

 the stress of war, when German U-boats wantonly 

 destroyed everything and the Island food was restricted 

 to local resources, the potency of the Sechium was 

 realised, and on several occasions the sullen apathy 

 of incipient starvation was awakened into reviving 

 animation under its influence. The gourd was also 

 utilised during the time of construction of the Panama 

 Canal, when the Italian labourers had to be coerced to 

 use a sufficient fat ration in their food in order that 

 they might equal the output of their Canadian fellow- 

 labourers. 



Another valuable plant is Lycopersicum cerasiforme, 

 which provides an agreeable tomato food with 

 important antiscorbutic qualities. In the Salvage 

 Islets there is also Monizaa Edidis, the carrot fern of 

 Madeira, with a species of the apterous Deucalion, 

 otherwise known only on the Madeira rocks, side by 

 side with the Canarian Samphire astadamya ; this 

 seems to establish a balancing correlation or agreement 

 between the botanic and entomological features of 

 the two island groups. 



An interesting illustration of sterility yielding to the 

 introduction of a new pollen is afforded by a species 

 of the Bignoniaceous jacaranda, while the sterility of 

 the banana and the complete loss of fertility in the 

 fruiting Solatium guatemalense show, on the other hand, 

 how we are constantly curbing the superabundant 

 seed growth of valued sub-tropical fruits, such as the 

 custard apple and the loquat, which in the fruit-vacant 

 months of Northern Europe should flood British 

 markets both in perfection and profusion. 



Many introduced plant pests, such as Peronospera 

 and Oidium, have been brought under control, and 

 even the Phylloxera vas/alrix, which destroyed tin- 

 Madeira vineyards before its life-history was made 

 out. has become almost negligible in its depredations ; 

 thus the wine of Madeira has returned in adequate 

 and superabundant supply. The Argentine ant may 

 be 1 redited to some extent with restraining the activity 

 of the Phylloxera aphis. In view of the almost certain 

 invasion of the British Islands by this pest, the Board 

 of Agriculture should issue and circulate the American 

 official booklet on the subject, together with a reprint 

 of a paper read by me before the British Association 

 two years ago. No less than 47,000 of these ants 

 have been found engaged in draining a single lemon 

 tree of its vitality; but various agencies of restraint are 

 now employed in the orange and coffee plantations. 

 The common flea and the house-fly do not seem to have 

 abated under the domination of the Iridomyrmex. 



The winged ant-queens suffer deflation after mating, 

 and, discarding the cares of motherhood, they issue 

 forth with the workers and found new colonies wherever 

 conditions invite. The intelligent ingenuity of the 

 ant and its tenacity of purpose in the face of obstacles 

 is very remarkable. 



NO. 2749, VOL. I 10] 



As regards oceanic research, organised exploration 

 of the ocean flora and deep-water biology is urgently 

 necessary in the national interest. This investigation 

 is a part of our responsibility in Imperial expansion ; 

 a second Challenger expedition is long overdue, and 

 could be accomplished at a comparatively small cost. 



The fisheries of Madeira provide several novel speci- 

 mens. The Sherny, Poly prion Cernier, freshly brought 

 from the deep sub-tropical water of the Madeira dis- 

 t liit , is typical of the warmer seas, though occasion- 

 ally seen farther north. This is the wreck fish of 

 British nomenclature, so known from its association 

 with floating timber logs. The early life of the fish is 

 passed in the sunlit surface waters, but the proper 

 habitat of the full-sized creature, 100 lbs. in weight 

 or more, is in the open sea at the enormous depth of 

 2000 or 3000 ft. 



The fish, when brought to the surface from that 

 profound depth, so distends at the removal from the 

 vast pressure below that it emerges from the water 

 like a cork or bladder, with its stomach forced through 

 the capacious mouth and the eyes protruding in front 

 of their sockets. No explanation is known of the 

 conditions which prompt the fish to descend from the 

 surface warmth into the cold darkness of the abysmal 

 region, where only the larger examples are to be found. 

 That the sea is nowhere azoic is shown by the plump 

 and well-fed condition in which the Sherny comes to 

 the surface. Its dull colouring, which is shared by 

 the Aplurus and Promethus Allaiitiats, contrasts sur- 

 prisingly with the brilliant hues of Sebastes. Scorpcena, 

 and Lampris, which also live in the depths, though 

 rarely in close association with their sober-tinted 

 brethren. The Sherny has a large air-bladder 

 firmly attached to the spine, but knowledge of the 

 function of this organ is very imperfect. The regula- 

 tion of submersibility by a voluntary act of filling, 

 emptying, or compressing is probably only a subordi- 

 nate physiological function, for the structure of the 

 bladder is suggestive of pulmonary functions, and its 

 firm attachment to the spine and its prolongation 

 upwards to a cerebral connexion with the organ of 

 hearing, seem a sure indication of the use of the organ 

 as a resonator in the interpretation of weak sonorous 

 vibrations. The air-bladder, nevertheless, is totally 

 absenl from the Aplurus and many other fishes. 



Some of the fishes swimming near the surface are 

 believed to have their air-bladders charged with 

 nitrogen, but extensive observation does not confirm 

 the current idea that in deep water oxygen is the 

 inflating gas. The consumption of oxygen by fish is 

 small, and the standard of respiration in oceanic fish 

 of deep water is low ; the heart-beat in the Polyprion 

 will continue many hours after every other sign of life 

 has ceased. Stationary traps are necessary for the 

 investigation of the abysmal forms of life. 



The surface plankton is abundant, but the con- 

 tracted empty stomachs of some of the deep-sea fish is 

 evidence against the idea that much food is dissolved 

 in deep-sea water. The Aphanopus Carbo is a voracious 

 monster which abounds in the lesser depths, and 

 ranges freely among the inexhaustible invertebrates 

 of those regions. 



During a series of observations on earth-currents in 

 deep-sea cables, strange effects were noted which were 



