74 



HARDWICKE'S SCIENCE-GOSSIP. 



— for, in many cases progeny are actually nursed 

 and protected by the parent, even supported and 

 supplied with untiring zeal. As a rule insects are 

 only destructive in a larval state — destructive, in many 

 instances, in the sense of being beneficial. In that 

 condition, development is rapid, and the chief 

 business of life, i.e., the preparation for a higher and 

 more important condition, is performed. 



In consequence of the minuteness of eggs of insects, 

 and the extraordinary care taken in depositing them, 

 they frequently baffle detection, but it is certain 

 few localities escape, and they may be sought for in 

 the most unexpected, and apparently unlikely places. 

 Many singular instances might be mentioned : the 

 larvae of the Curculios feed on the developing seeds 

 of plants, the eggs are deposited in the flowers, 

 and during growth, the hatched larvae bore through 

 the soft tissues of the "receptacle," and devour its 

 contents. In the larger order of the lepidoptera 

 extraordinary care is exhibited, even to the extent of 

 mechanically providing protection by enveloping the 

 eggs in peculiar coverings, or securing a defence with 

 glue-like varnishes of considerable tenacity. The life- 

 duration of the egg condition, is often a factor. Many 

 moths only deposit on fruits just ripening, a matter of 

 days, and adjustment of time ; unripe fruits are never 

 touched. The cocci, or scale insects (infesting peach- 

 houses, and conservatories), fix themselves firmly on 

 the leaves and brood over the eggs ; even after death 

 the body forms a tent or covering under which the 

 young remain until mature. 



The orthoptera dig holes in the earth and deposit 

 eggs in groups, enveloped in some instances in a case. 

 As in this order the young when hatched immediately 

 exhibit the lively appearance, appetites, and instincts 

 of the parents, and are capable of at once seeking 

 food, a storage of provision, or a contiguous supply- 

 is unnecessary. Living and growing tissues are 

 often the nidus and receptacle of eggs. The gad-fly 

 (Tabanus) has a sheath capable of penetrating the 

 skins of animals, and not only depositing the egg, but 

 of setting up a condition of excitement necessary for 

 the future preservation of the young. The means 

 and instruments employed are endless ; the various 

 forms of ovipositors is a subject in itself. They are 

 capable of cutting into, and boring beneath the 

 cuticles of leaves or the rinds of fruits, leaving an egg 

 in the parenchyma, with the addition of a corrosive 

 fluid of such virulence as to excite abnormal growths in 

 aid of the sustenance of the future larva;, producing con- 

 tortions of tissues, and excrescences, as in the well- 

 known gall-nut ; a curious reciprocity as affecting the 

 functions of the plant, and the requirements of the 

 insect. 



Space does not admit the pursuit of this interesting 



subject ; our younger readers must be referred to 



Kirby and Spence's most charming Introduction to 



Entomology. 



Among remarkable forms may shortly be specified, 



the yellow eggs of the cabbage butterfly (Picris 

 brassica:), the puss moth (Centra vinula), the privet 

 moth (Sphinx ligustri), the transparent eggs of the 

 honey bee, the cockroach, the cricket, and the eggs 

 of most of the parasites, especially those infesting 

 the pheasant. Many of these open longitudinally 

 through well-marked sutures aided by the tension of 

 curvature. For the cabinet, eggs are easily prepared 

 as opaque objects, and it is not difficult to arrange 

 them for observation on the stage of the microscope, 

 in a living condition, showing the movement of the 

 larva within, and with patient watching, its ultimate 

 emergence. 

 Crouch Hind. 



GOSSIP ON CURRENT TOPICS. 

 By W. Mattieu Williams, F.R.A.S., F.C.S. 



AVERY interesting paper on labour and wages in 

 America was read at the Society of Arts by 

 Mr. D. Pigeon, the Hon. J. Russell Lowell in the 

 chair. Among many other facts proving the superior 

 education afforded to artizans there, he showed that 

 the number of public schools in the United States is 

 225,800, or one to every 200 of the entire population 

 of both sexes and all ages. In Massachusetts alone 

 there are nearly 2000 free libraries, or one to every 

 800 inhabitants. No wonder then that Mr. Lowell 

 was able to say that "one thing he thought he had 

 noticed in the real American workman, was the 

 amount of brains which he mixed with his fingers," 

 as compared with the workmen of other countries. 

 Now that science is interfering with every kind of 

 industry, this ability to mix up brains with fingers 

 will determine the destiny of nations. Not only the 

 arts of peace, but also the grim business of war, is 

 dependent upon science. The victory of the Germans 

 in the Franco-Prussian war was largely due to the 

 mixing of brain with fingers, in the handling of 

 delicate arms of precision, and the intelligent use 

 of maps by common soldiers. 



At the meeting of the Chemical Society, on 19th 

 February, Mr. E. C. H. Francis described a simple 

 but very valuable discovery, viz., that if filter paper 

 be immersed in nitric acid of 1*42 sp. gr., and 

 washed in water, it becomes remarkably toughened 

 without losing its porosity, as when treated with 

 sulphuric acid in making parchment paper. We are 

 told that the paper treated with nitric acid may be 

 washed and rubbed without damage, like linen. It 

 contracts and loses a little weight, but contains no 

 nitrogen. The weight of its ash diminishes, which is 

 an advantage in analytical chemistry, especially in 

 rough and ready commercial analyses where the ash 

 is neglected. As non-chemical readers may not 

 otherwise appreciate the important position held by 

 filter paper in an analytical laboratory, I will explain 



