3 86 



SCIENTIFIC NEWS. 



[Oct. 12, IS 



vates funnels filled with a liquefied substance, in which 

 are found abundance of longer or shorter filaments filled 

 with very small spores, perfectly rounded and regularly 

 distributed. They are stained only by Erlich's reagent, 

 and that after some hours. Along with these filaments 

 are found free spores and some movable rods, which 

 become spore-bearing filaments. In pure gelatine these 

 filaments are not luminous, but if they are transferred 

 into liquids of an alkaline reaction, suitably salted and 

 containing phosphorised nitrogenous matter (nucleines, 

 lecithines, etc), they emit a fine blueish phosphorescence 

 in the parts exposed to the air. We find, then, scarcely 

 any filaments with spores or movable rods, but almost 

 exclusively spores. 



These luminous liquids obey the same influences as 

 the luminous tissues of phosphorescent animals. 



Further, we see in the culture-liquids an accumulation 

 of that characteristic birefrangent substance which forms 

 the chalky layers of the Pyrophori, the Lampyrida;, the 

 Podurae, and which is found in the tissue of the syphon 

 of the pholas, in the epithelium of the digestive tube of 

 phosphorescent myriapods, etc., and the existence of which 

 we have recognised even in the phosphorescent sea-water 

 of the port of Mentone. 



This substance, which resembles leucine in certain 

 respects, presents in culture-solutions all the forms which 

 we have met with in the animals studied : fine rounded 

 birefrangent granulations, either homogeneous, or having 

 at their centre a brilliant part representing a vacuole 

 (Vacuo! ides) ; rounded corpuscules, scintillating in po- 

 larised light (sphero-crystals) ; or small radiating or 

 isolated prismatic needles. We may easily follow all these 

 transformations of one and the same substance, which 

 we have considered as forming one of the elements 

 of the photogenic reaction, when it now seems, according 

 to our most recent researches, to be merely the result. 



Along with this product which is deposited in the 

 phosphorescent solutions, as in the organs of luminous 

 animals, we find a considerable quantity of crystals of 

 the double phosphate of ammonium and magnesium, and 

 of carbonate of lime, and in the liquor alkaline phos- 

 phates in solution. These phosphates are almost entirely 

 formed by the oxidation of the phosphoric nitrogenous 

 matter contained in the solution. We must admit that 

 these phosphoric nitrogenous matters, though not directly 

 oxidizable in the air, yield, under the influence of the 

 ferment, a substance which possesses this property. 



The researches enable us to reconcile the theory of a 

 photogenic fermentation with the hypothesis of the oxi- 

 dation of a phosphoric matter. 



It explains the role of the alkaline and saline blood in 

 the acid photogenic tissues of the Elateridae and Lampy- 

 ridse, which we have observed without being able to 

 explain. Lastly, we conceive how the phosphorescence 

 of the sea may be produced by the disagregation of 

 marine animals. 



NOTES FOR YOUNG COLLECTORS. 



{Continued from p. 178.) 

 TN our last notes, whilst speaking of rivers in flood as 

 ■*■ often yielding a harvest for the entomologist, we 

 omitted to call attention to the rubbish which streams 

 deposit along their banks above the ordinary high-water 

 mark after heavy rains. This rubbish consists of grass, 

 straw, twigs, reeds, etc., and often conceals numbers of 

 insects, especially beetles and land and fresh-water 



shells which have been swept away from the banks, the 

 bushes, and the adjoining fields. The search should not 

 be long delayed, or the insects will have had opportunity 

 to make their escape. 



There are various baits, artificial or provided by 

 nature, to which insects resort very eagerly. Among 

 such may be mentioned holes bored into a tree with a 

 large gimlet, so as to set the sap flowing. This is espe- 

 cially attractive in spring and the early part of summer. 

 Excrements of various animals and dung-heaps are often 

 visited not merely by two-winged flies and the so-called 

 dung-beetles of which the species are multitudinous, but 

 by the most beautiful butterflies. A dead rat, mole, or 

 weasel nailed to the stem of a tree at a convenient 

 height is an excellent bait for the "purple emperor" 

 (Apalura iris). The gorgeous papilios and ornithopteras 

 of hot climates will come down from the tree-tops to 

 recent human excrement and to over-ripe fruits. Per- 

 haps a half-rotten banana is their favourite lure. 



Another trap for a great variety of insects seems quite 

 unnatural, and is yet very successful. It is simply a 

 white cloth spread out on the ground and examined 

 from time to time on both sides, both by day and by 

 night, of course in the latter case by the aid of a lamp. 

 This method of trapping is practicable only either in very 

 unfrequented places or in private enclosures. Elsewhere 

 the cloth will often be found to disappear altogether. 



In warm climates it is very necessary to kill all in- 

 sectivorous creatures which may visit the cloth, such as 

 scorpions, centipedes, tarantulas, galeodes, etc., or they 

 will take the first choice among the specimens. 



In waste grounds, especially if sandy, gravelly, or 

 chalky, and covered only with a scanty vegetation, good 

 work may be done by digging holes with a garden 

 trowel, making the sides steep. Insects which do not 

 fly when taking their excursions by day or night get in, 

 and cannot get out again. Such holes should be visited 

 early in the morning. 



Many night-flying species, both moths and beetles, can 

 be captured by the aid of lights properly fixed. An 

 electric light, or in its default a powerful paraffine lamp, 

 with a good reflector, is fixed either within a room with 

 open windows or in a verandah. The best situation is 

 an eminence overlooking woods, gardens, or fields, and 

 the best time is the absence of moonlight. . The collector 

 waits at hand with his net, and captures the insects as 

 they rush to the light. There are also lamp-traps, 

 which dispense with the net, though not with the attend- 

 ance of the collector, as if not promptly captured the 

 specimens will damage themselves with fluttering. 



A very common method of catching moths, especially 

 of the Noctua group, is " sugaring." A part of a tree- 

 trunk, at a convenient height, is painted over with a com- 

 position, of which coarse sugar is the principal ingre- 

 dient. Rum or stale beer is added, to bring the whole 

 to the consistence of a thin paste. On calm, dark nights 

 the collector goes round with a lamp, examines the 

 sugared trees, and dextrously encloses the moths in 

 pill-boxes, transferring them then to the " killing-glass," 

 where they inhale the vapour of cyanide of potassium. 

 Various beetles, even some of carnivorous habits, will 

 also come to sugar. The beetles, if desirable, can, of 

 course, be captured. Spiders occasionally appear, and 

 earwigs in great numbers. They are, of course, treated 

 as poachers, since they frighten away the moths. 



In all these various methods of collecting, take care, as far 

 as possible, that you are not watched, especially by boys. 



