15S 



HARDWICKE'S SCIENCE-GOSSIP. 



[July 1, 1863. 



THE CUCKOO-SPIT. 



rjlTTO of these little insects (Jp/iropkora spu- 

 -"- maria), known to be females by their full- 

 length wing-cases, were removed in November from 

 the garden to a small plant-case, with a view to 

 discover where they lay their eggs. Their first 

 efforts were to escape, but in a day or two they 

 settled down to their usual quiet ways, sitting on 

 the leaves to enjoy the brief autumnal sunshine, and 

 then retiring among them. By the middle of 

 December they had finally disappeared. One dead 

 insect was afterwards found, but the eggs could 

 not be discovered by the most careful search. They 

 were certainly there, for half a dozen larva; were 

 hatched early in the following April. The con- 

 clusion arrived at is that the eggs are deposited in 

 the ground about the roots of plants. They must 

 be large for so small an insect, and therefore few 

 in number, judging from the size of the newly- 

 hatched larva. This at once commences operations 

 on some juicy stem or leaf— no matter what, so it be 

 sappy enough ; thrusts in its long proboscis, pumps 

 up the sap, blows it off in small bubbles through a 

 pipe at the tail, and so speedily constructs for itself 

 a cool, moist, translucent home. Here it revels in 

 abundance through the spring months, when, grown 

 to maturity, its first and only change is made. It 

 ceases to renew the bubbles, its moist habitation 

 exhales in the summer heat, the insect is glued to 

 the twig, the skin splits, and it frees itself, leaving 

 a perfect exuvium behind. Its appearance is not 

 much changed, except in the important particular 

 of colour, which is now a mottled brown. It is 

 winged, and can make a short flight, throwing itself 

 into the air, when alarmed, with a jerk of the hind- 

 most legs. It lives in the sunshine on the leaves, 

 only blowing a bubble into the air now and then, as 

 in sport ; but it continues probably to feed on the 

 sap of plants, for its proboscis is retained, and in 

 some few individuals a second is provided, like a 

 child's second set of teeth, ready to take the place 

 of the first when wanted (an interesting fact which 

 deserves a fuller notice). Its skin is cast but 

 once, and must therefore grow with it, and here may 

 perhaps be seen a reason for its curious economy. 

 The crickets and grasshoppers, which undergo a 

 similar change, live in or near the ground, and find 

 sufficient moisture there to keep their skins humid 

 and pliant ; but the cuckoo-spit, high up on the 

 leaves and stems of plants, must provide itself a 

 bath. 



This little hopper can never be a favourite with 

 the florist : it intrudes itself so perseveringly, un- 

 conscious of its bad name and questionable ways, 

 into our gardens and conservatories ; but the natu- 

 ralist who studies the instincts of animals, and loves, 

 may be, to trace the wideness of that tender care 

 which is over even the most humble creatures, will 



regard it with complacency and interest. If a 

 microscopist, he may place the young larva gently 

 on the stage in a drop of water, and view by strong 

 transmitted light its whole internal economy — the 

 constant heaving of the blowing tube, the motion of 

 the intestines, and the boat-shaped corpuscules of 

 the blood circulating, not through veins, as in the 

 frog, but along the interstices of the limbs and body. 

 By a little management it can be brought to feed 

 under the microscope, and display the spiral motion 

 of the curious pump in its horny case between the 

 eyes. The gauzy underwing may be mounted to be 

 viewed by reflected light ; it is a lovely opaque object 

 with its delicate pearly lustre. 



This season the larva is most abundant, and 

 should be carefully, as it may be easily, studied. 



S. S. 



EXHIBITION OE INSECTS IN PARIS. 



An exhibition of useful and destructive insects is 

 announced to take place in the Palais de l'lndustrie, 

 under the patronage of the Minister of Agriculture, 

 during the month of August. It will be remem- 

 bered that an exhibition of the same kind, on a 

 small scale, was held in the same building in the 

 year 1S65, through the efforts of the Central Society 

 of Apiculture ; that first attempt gave rise to the 

 formation of a new society of agricultural in- 

 sectology, and it is this latter association which is 

 entrusted with the organisation of the coming exhi- 

 bition. The committee includes Dr. Boisduval, 

 M. H. Hamet, M. Guerin MeneVille, M. Eocillon, 

 and several other entomologists and scientific agri- 

 culturists. The exhibition is to be made' as com- 

 prehensive as possible, the scheme including the 

 propagation of useful insects, methods of curing or 

 preventing disease, and economical management ; 

 and the illustration of destructive insects, with 

 means for opposing their ravages. It is desired that 

 each class should, if possible, be exhibited in all its 

 transformations, from the egg to the perfect insect, 

 together with the matters on which it feeds. Printed 

 or written memoirs are also to be admitted, even 

 without specimens of the insects to which they 

 refer. As regards destructive insects, the society 

 has determined on a practical instead of a scientific 

 classification, the subdivisions being formed by the 

 plants uponwhichthe creatures feed. Two additional 

 divisions are added to the programme of the exhi- 

 bition ; one including carnivorous insects, and small 

 mammiferous animals, such as the mole and hedge- 

 hog, which feed on insects ; the other being devoted 

 to the illustration of the ravages committed by snails 

 and slugs. Some idea of what this amounts to in 

 the vine-growing districts of Prance, may be formed 

 from the fact that thousands of bushels of snails are 

 collected in the vineyards and sent to various markets 



