244 



KNOWLEDGE & SCIENTIFIC NEWS 





[Oct., 1904. 



appear to shatter the walls of their prison by giving a violent 

 wriggle. They do not immediately obtain freedom, however, 

 but still remain encased in the inner membrane of the shell, 

 which is rnptured some hours afterwards. 



When first hatched the primaries and secondaries are 

 ensheathed in a " thin filmy covering " which gives the wings 

 the appearance of being still undeveloped, but directly the 

 chick dries this membrane peels off, leaving the bird ready for 

 flight. 



At three weel;s the black feathers of the adult plumage 

 are distinctly visible through the " down," and at six weeks 

 the birds are almost indistinguishable from the parents. 



* * * 



Breeding of the Tataupa Tinamou. 



(Crvptuyns tataupa.) 



Mr. Seth-Smith is the first to have succeeded in breeding 

 this rare bird in confinement, and as nothing was hitherto 

 known of its habits at this time his short description thereof 

 in the AviciiHural Magazine for August is of considerable 

 interest. 



The eggs are incubated by the male only. From the 

 moment he began to sit the female resigned all interest in the 

 matter: indeed, if she approached, her mate rushed at her open 

 mouthed so that she fled in terror ! Before leaving them the 

 eggs were most carefully covered up. After the escape of the 

 young from the egg shell the male broods them for some hours 

 before bringing them out into the open. 



The female does the courting, calling to her mate and then 

 running to him, and displaying in the most curious attitudes. 



When alarmed these birds adopt the peculiar device of 

 throwing themselves forward on the breast and throwing the 

 tail in the air so that the under-tail-coverts form a screen to 

 hide the body ; which in consequence becomes hard to dis- 

 tinguish from the surrounding herbage and undergrowth. 

 Even very young chicks, when they suspect danger, squat and 

 turn up their sprouting tails, but whether instinctively or in 

 imitation of the parents the author does not say. 



* * * 



The Weight of Eggs. 



In our last issue, it will be remembered, we referred to a 

 paper on the loss of weight of eggs during inculjation. The 

 /o.)loi;ht for August contains some extremely interesting notes 

 on the range of variability in the weight of eggs of wild birds, 

 which is much greater than one would have imagined. The 

 eggs of the Charadriidje were used to furnish the matei'ial for 

 this investigation, and the strictest care was used to select 

 only unincubated eggs, thus eliminating the error due to loss 

 from this cause. The weight of the whole clutch, and not of 

 single eggs, is given. Altogether, about a dozen species have 

 been studied in this connection, and four or five clutches of 

 each species have been weighed. In Jigialits hiaticula, the 

 lightest clutch weighed 45'i48 grammes, the heaviest 50'450 

 grammes; in Charadrius pluvialis the differences were ijO'iOy 

 grammes and isi-agg grammes; in I'aiwtlus vulgaris, io6'62i 

 and iiy434 grammes; in Numciiiiis arquatiis, 320'ii4 and 

 348'ii6 grammes; in Totanus caliiiris, 82'i64 and g2'6S7 

 grammes. It would be interesting to compare the relative 

 differences in weight between the birds of the species 

 enumerated and their egg clutches, and to note the difference 

 between the activity of their young on hatching. So far, no one 

 seems to have noticed whether this differs to any appreciable 

 extent among the different species of Charadriid;e. 



* * * 



The Systema.tic Study of Bird Life. 



The foundation of an Ornithological Observatory is an 

 event which may be said to mark an epoch in the study of 

 ornithology. Such an establishment has just been started in 

 the United States. It is to be known as the " Worthington 

 Society for the Investigation of 15ir<l Life," and has been 

 erected and endowed by its founder, Mr. C. C. Worthington. 

 on his estate at Shanee, Monroe County, Pennsylvania. 



The programme laid down is exhaustive in its comprehen- 

 siveness, but we may draw special attention to one or two of 

 its particularly interesting items. In the first place particular 

 attention is to be paid to life histories. Observations on an 

 elaborate scale are to be made so as to embody as many 



details as possible concerning the growth, food, and habits of 

 individuals in a wild state. The study of the vexed question 

 of variations, their nature, and cause ; and colour changes 

 with respect to age, sex, moult, season, and climate should 

 yield much. The problems of heredity, experiments in hybri- 

 dising, and psychological observations are to be carried on in 

 specially constructed aviaries. Another important feature is 

 the proposal to test the possibility of breeding insectivorous 

 and otlier useful birds with a view to re-stocking depleted 

 areas, as has been done in the case of fish by the Fish Com- 

 mission. 



The carrying out of this great enterprise has been entrusted 

 to Mr. W. E. D. Scott, tlie Curator of the Ornithological 

 Department of the Princeton University. This augurs well 

 for its success ; indeed we know of no other man who is so 

 peculiarly fitted for such a task. He will be aided by a staff 

 of assistants. 



We cannot refrain from expressing a desire to see a similar 

 institution at work in this country. Perhaps the Board of 

 Agriculture may be induced to consider the matter. 

 # * * 



Snap-shots from Bird Life. 



We have peculiar pleasure in bringing to the notice of our 

 readers a very wonderful collection of stereoscopic pictures 

 which have just been issued under the above title. Every 

 picture has been taken from life — and about their genuineness 

 there can be no question — by M. P. L. Steenhuizen, of Amster- 

 dam. Though these photographs were taken in Holland, all 

 the birds in the series occur in Great Britain. A more mar- 

 vellous and a more beautiful collection it would be impossible 

 to imagine, and at the present time they are probably unique. 

 Since there are no less than 48 slides in all, we cannot give a 

 list of the subjects, and we find it peculiarly difficult to select 

 any for special mention, for all are alike exquisite. But to 

 give an idea of the variety of the selection, we may mention as 

 especially striking the nest and eggs of the pheasant, the nest 

 and young of the marsh harrier, the nest and young of the 

 spoonbill, the nightjar and its eggs, and the nest and eggs of 

 the great reed warbler. 



I shall be glad to give p.articulars to those who may desire 

 to procure copies of this really wonderful series. 



PHYSICAL. 



Electrical Wave Measurement. 



In the June number of " Knowlkdge," a description was 

 given of the means which Professor J. A. Fleming, F.R.S., 

 employs to investigate the propagation of electric waves along 

 spiral wires; and a diagram was appended to show the vvay in 

 which the apparatus can be employed for measuring the length 

 of waves used in wireless telegraphy. We reproduce the dia- 

 gram again below : — 



A, B.— Long: coil of 5,000 turns ot 



No. 36 wire. 

 W. -Earth Wire. 

 Li. L^. — Leyden .lars, each "0014 



mfd. capacity. 

 X. — Variable Inductance Coil, 0-230 



microhenrys. 

 I. Induction Coil— 10 inch spark- 

 S. — 5park halls. 



In practice the method consists of establishing stationary 

 electric waves on the spiral wire, and of deducing, by mathe- 

 matical reasoning, the wave length of the induced wave. The 

 experiments described previously in " Knowledge " were 

 made with a long helix of insulated copper wire, wound in one 

 layer on a wooden rod. Wood, however, has since been 

 found to be unsuitable for obvious causes ; and an ebonite rod 



