December 7, 191 1] 



NATURE 



191 



length of about 15 mm. — which it does in three days — the 

 ninth quill of the first plumage is moulted and replaced 

 in a similar manner. After this the eighth, seventh, sixth, 

 fifth, fourth, and third quills are successively shed and 

 replaced, but at regularly increasing intervals, the rate of 

 the development of their successors during twenty-four 

 hours decreasing in the same order. The second and first 

 quills are not shed at all during the first moult, but persist 

 until the completion of the second moult, in September or 

 October of the following year. This renders it possible to 

 etermine during a period of fifteen or sixteen months 

 whether a partridge is young or old, the tip of the first 

 _uill being pointed up to that age and rounded subse- 

 quently, .■^fter this period age-determination by the 

 plumage is impossible. The author adds that, by follow- 

 ing the formula given above, the exact age of young 

 partridges is determinable during the time that quill-moult- 

 ing is in progress, although it has to be borne in mind 

 that there may be a small "personal equation," some 

 individuals moulting slightly in advance of, and others 

 behind, their fellows. 



In this connection it may be noted that Country Life of 

 October 21 contains an article by the present writer on 

 the breeding-ages of birds, in which attention is directed 

 to the imperfect state of our knowledge on this subject. 



The results of an expedition to the pheasant-countries of 

 ^-''n are recorded by Mr. C. W. Beebe in the July issue 

 ntly to hand) of the New York Zoological Society's 

 i'tin. It is stated that " this expedition, organised for 

 the purpose of gathering original data for the preparation 

 of a monograph of the pheasants, jungle-fowl, and pea- 

 fowl, and made possible by the generous gift of Colonel 

 A. R. Kuser, has been completed. The most sanguine 

 expectations were exceeded in the amount of territory 

 covered and the results attained. Voluminous notes have 

 been taken, reinforced by a great number of photographs 

 I (some of which are reproduced in the article) and sketches, 

 I concerning the habits and ecology of the pheasants found 

 I in the countries visited, much of the material being new to 

 I science. Although the collecting of living birds was a 

 ndary object of the expedition, several large shipments 

 ' sent back." In the same number it is stated that 

 „ .,:male passenger-pigeon now in the Cincinnati Zoological 

 Gardens is believed to be the last living representative 

 of that once abundant species. 



The need of a longer close season for the Australian 

 stubble-quail (Cottcrmx pectoralis) is strongly urged by Mr. 

 G. A. Keartland in the September number of The Victorian 

 Naturalist. For a short time the close season was from 

 August I to December 20 ; it was extended at different 

 times to February i, March i, and April i ; but this year 

 it has been put back to February 14, which the author 

 urges is much too early, as many of the broods are then 

 "cheapers." ' R. L. 



THE SEVENTEEN-YEAR CICADA. 

 T^HE Cicadidae are an interesting group of insects, which 

 chiefly inhabit warm countries. They are represented 

 in England by a small species (Cicadetta montana) which 

 is almost confined to the New Forest, where it is scarce 

 and local. In classical times they were known under the 

 name of Tettix, and the loud stridulation of the males 

 attracted much attention. As in England, so in the eastern 

 United States, there is only one species which is common 

 and woll known, Tibicina septcndccim, the peculiarity of 

 which is that its life-cycle occupies seventeen years in the 

 northern, and thirteen in the southern. States, and only at 

 these intervals are they specially abundant. In America 

 they are often improperly called locusts, and are reckoned 

 among destructive insects, for the larva feeds on the roots 

 of trees ; and it is ranked among injurious insects. 



The eggs are laid on the twigs of trees, and when the 

 larvje are hatched they drop to the ground and gather in 

 clusters on the roots, from which they suck the sap. The 

 pupa-state lasts only a few days, and when ready to emerge 

 they form galleries, through which they ascend to the 

 surface of the ground, and emerge, leaving their cast skins 

 behind them. The perfect insect is easily recognisable, 

 having a short, broad black body rather pointed at the 

 hinder extremity, and four long and modf^rately broad wings 



with conspicuous reddish nervures, the fore wings being 

 considerably larger and more pointed than the hind wings. 



The Times of November 3 directs attention to the 

 emergence of numbers of these insects during the last 

 summer from the soil in the Bronx Zoological Park in New 

 York ; but when the writer adds, somewhat incon- 

 sequentially, " It is probable that the species is approaching 

 extinction in view of modern conditions of cultivation, and 

 the extension of building areas," we imagine that the con- 

 tingency can hardly be so near as he supposes, although 

 the complete extermination of once common insects in con- 

 sequence of the changed conditions to which he refers is 

 no uncommon occurrence. W. F. K. 



SCIENTIFIC PROGRESS AND PROSPECTS.' 



A LL advance in the relations between man and nature 

 "^ whereby man gains to any greater extent the mastery 

 may be described as scientific progress ; and in this con- 

 nection we must recognise that many things which we 

 now look upon, and have for ages regarded as entirely 

 commonplace, were, at the time of their inception, really 

 very remarkable indeed. Take, for instance, the applica- 

 tion to human needs of fire. Animals, even of the highest 

 types, make no use of it. There must have been a period 

 when man also did not understand its properties, and, like 

 the animals from which he has sprung, was afraid of it 

 and left it severely alone. A time must next have come, 

 and with that time the valorous man who first had the 

 temerity to experiment with this very powerful and 

 destructive agent. 



Think of this prehistoric investigator into the means and 

 effects of combustion in that far distant age ; consider his 

 inferior mental equipment ; imagine his savage surround- 

 ings ; take into account, also, his lack of any but the most 

 primitive appliances. Must we not laud his enterprise and 

 admire his courage? Must we not also acknowledge the 

 enormous advantages his investigations have gained for all 

 his posterity? The warming of their bodies and the cook- 

 ing of both animal and vegetable nutriment would, no 

 doubt, be the first uses to which our remote ancestors 

 would apply the new agent ; but soon would follow the 

 firing of pottery, up to that date merely sun-baked, then 

 the reduction and smelting of metals, and finally the whole 

 galaxy of the arts. What is scientific progress if this is 

 not? And yet it leaves off where what we usually mean 

 by science begins, namely, about the Gra:co-Roman period. 

 Look out, however, into London to-day, and recognise how 

 little of all we see around us could have ever existed but 

 for those early high-temperature experiments made so many 

 thousands of years ago. Without them, could human 

 beings even live in this northern climate? 



Here may I point out that, curiously enough, it is only 

 when we go back to the earliest evidences of primitive 

 human life upon this planet that we take the true philo- 

 sophical course of naming the periods we are dealing with 

 after the main material advances in scientific progress 

 made during those periods by the human race. We talk 

 of the Stone age, of the Bronze age, or the_ Iron age, to 

 denote those vast expanses of time during which the primi- 

 tive inventor was discovering the means of applying new 

 materials to what was then the great necessity of man- 

 kind, namely, weapons for the chase, for self-protection, 

 and for war upon his enemies. , . , 



Later in history we find that this really philosophical 

 method is abandoned. As we come to know more as 

 regards the position, supremacy, and conditions of par- 

 ticular races, and still further when we become better 

 acquainted with the deeds and achievements of particular 

 individuals, we find that hist&rians have a tendencv to 

 overlook the enormous influeno' of the results obtained by 

 scientific investigators and discoverers, and to make it 

 appear as though the current of events were really governed 

 by those who. from accident of birth. oflRcial position, 

 political influence, or martial achievements, have made for 

 themselves reputations as leaders of men. 



To see that this view is wrong we have only to survey 

 the past. Can it for an instant ho doubted that the labours 

 of the unknown prehistoric individual to whom I have just 



1 From the preRideiitial address delivered to the Ri5ntgen .Society on 

 November 7 by Mr. A. A. C.-impbell Swinton. 



NO. 2197, VOL. 88] 



