June 1, 1894.] 



KNOWLEDGE 



121 



AN ILLUSTRATED 



MAGAZINE OF SCIENCE 



SIMPLY WORDED-EXACTLY DESCRIBED 



LONDON: JUNE 1, 1894. 



By the Rev. Alex. S. Wilson, 



Star ? Bv Miss A. M. C'lekke 

 By 



CONTENTS. 



Insect Secretions.— II. By E. A. Butler, B.A., B. So. ... 

 The Luminiferous Ether. By J. J. Stewakt, B.A.Cantab., 



B.Sc.Lond 



The Genesis of Flowers 



M.A., B.Se 



Is Beta Lyrae a Double 



The Fatigue of Metals, and Muscular Fatigue. 



D. S. Smart ■■• 



Star Clusters in the i) Argus Region of the Milky Way. 



By A. C. Rantaed 



Liquid Chlorine. By A. G. Blosam 



Science Notes 



Letters:— A. Collisox ; William Noble; W. F. DenninO; 



Edwin Holme.s; J. Munro; F. Montague James; 



J. T. Denham 



The Venom of the Cobra. By C. A. Mitchell, B.A.Oxon 



" Rib-Walkers. ' By R. Ltdekkee, B.A.Cantab 



The Wood-Pigeon. By II.\eey F. Witheebt 



The Face of the Sky for June. By Hbebert Sadlee, 



P.R.A.S. 



Chess Column. By C. D. LocooK, B.A.Oion 



PAGE 

 121 



12.3 



12.5 



128 



130 



131 

 134 

 134 



135 

 137 



1.3S 

 141 



142 

 143 



INSECT SECRETIONS.-II. 



By E. A. Butler, B.A., B.Sc. 

 [Continued from page 106.) 



FOR wax, our second illustration of insect secretions, 

 we must go first of all to the order Hymenoptera, 

 as yielding that variety of animal wax which is 

 best known and most widely used iu the Western 

 world. But the production of waxy substances is 

 not confined to hymenopterous insects ; for example, while 

 European wax is the produce of the hive bee, the white 

 insect wax of China owes its origin to an entirely difl'erent 

 insect, belonging to the orderHomoptera, and to that section 

 of it called Cocciihe, or scale insects. And, in fact, the 

 power of secreting matter varying from a waxy to a more 

 or less silky consistency is widely diffused throughout this 

 latter order ; the makers of these substances, however, do 

 not use them, as bees do their wax, for constructive pur- 

 poses, but the secretions generally exude in the form of 

 long threads, which remain adherent to the insects as 

 personal appendages of either a protective or ornamental 

 character. The production of waxy and other allied sub- 

 stances is, therefore, associated with two very distinct types 

 of insect life — the hymenopterous, typified by the hive bee, 

 and the homopterous, typified by the scale insects. We 

 will first turn our attention to beeswax. 



It was long thought that the honey bee produced its wax 

 from the pollen of flowers, which was supposed to be 

 worked up and kneaded by its feet to the requisite con- 

 sistency. Nor was this idea unnatural, though erroneous. 



In the hive were to be found stores of honey and wax ; 

 the former it was known that the bees manufactured from 

 the nectar of flowers, and it remained, therefore, to account 

 for the wax in a somewhat similar way. On the bees' 

 legs were seen the masses of pollen they had also gathered, 

 and as the wax seemed more nearly akin to the solid 

 pollen than to the liquid honey, it was an easy supposition 

 that the two were related to one another as raw 

 material and manufactured product. So we find an 

 old writer stating that " from the flowers they gather the 

 wax with the hairs which cover their bodies, and when they 

 return from the fields you may see their hairs full of small 

 particles of wax like dust." This idea prevailed for a long 

 time, and it was not till late iu the last century that it 

 became generally recognized that wax was not a gathered 

 substance, but that it originated in the form of scales on 

 the under side of the abdomen of the worker bee. 



One of the earliest detailed accounts of the discovery 

 of its true source is contained in a book on bees, called 

 " Melisselogia, or the Female Monarchy," published in 

 1744. The author, .J. Thorley by name, who had for 

 some years devoted himself to bee-keeping, was anxious, 

 as he says, to " find out how or where they brought home 

 their wax," but for some time his eflbrts were balfled ; at 

 length, however, the favourable conjuncture of circum- 

 stances occurred, and the problem was solved. This is 

 how he announces his discovery: — "Viewing a hive of 

 bees very busy at labour, I observed one bee among the 

 rest as she fixed upon the alighting place, of an unusual 

 appearance ; upon which I seized her directly, before she 

 had time to enter the hive, where, with very sensible 

 pleasure, I found what I had (till then) been in vain 

 searching for. Upon the belly of this bee, within the plaits, 

 were fixed no less than six pieces of solid wax, perfectly 

 white and transparent, like gum ; three upon one side and 

 three upon the other, appearing to the eyes equal in bulk 

 and gravity, so that the body of the bee seemed duly 

 poised, and the flight not in the least obstructed by any 

 inequaUties. Here have I found it at other times, and 

 once I took away eight pieces together, and I knew that it 

 was wax and nothing else. WiU not this pass for demonstra- 

 tion ? " This observation showed that wax was not merely 

 pollen worked up— and was, therefore, chiefly valuable 

 as negative evidence — but there was much more to be 

 learnt ; for, as Thorley himself says, " how they manufacture 

 the wax, fix it to the hive, and fashion it in so curious a 

 manner into combs and cells, we cannot easily account for." 

 Thorley's discovery does not seem to have attracted much 

 attention, and in fact apparently remained unknown to 

 the scientific world ; for twenty-four years afterwards, 

 Wilhelmi wrote to Bonnet informing him of what was 

 evidently regarded as an interesting novelty, that a 

 Lusatian peasant, who' was an ardent bee-keeper, had 

 found wax scales attached to the abdomen of worker 

 bees, and had thus revealed the source of this useful 

 J j)roduct. A somewhat similar observation had been 

 ' recorded in Germany even before Thorley's time, so that 

 the truth was independently discovered in several places 

 ; and at different times. In the Philosophical Transactions 

 for 1792, John Hunter gives some very pertinent observa- 

 tions in refutation of the previously accepted notion of 

 the origin of wax from pollen. Thus, while the " farina," 

 as pollen was then called, was often of different colours 

 on the legs of difl'erent bees, the newly-made wax 

 was all of one colour; it was gathered with more 

 avidity for old hives, in which the combs were complete, 

 than for those in which the comb was still in course of 

 construction, which could not have been the case if 

 " farina " was the material out of which wax was made, 



