234 



NATURE 



Sjan 9, i8;9 



and whose intensity of scintillation is far smaller than that of 

 the other three. With regard to the effect of the star's own 

 colour it must be remarked that the relative frequency of that 

 colour or of a nearly related one is often very great ; thus, for 

 instance, yellow is very frequent in the yellow star a HydrjE, 

 and orange in the orange stars Betelgeuze and o Herculis. The 

 total number of observations M. Montigny made of these six 

 stars was 574. 



For the sake of comparison M. Montigny has calculated the 

 relative frequency of colours in two stars of the second type, to 

 which, as our readers will remember, our own sun belongs too. 

 The stars selected were Pollux, with a very characteristic spec- 

 trum, and Capella, which scintillates with great regularity. 

 Both stars are yellow and their spectra show very thin dark 

 lines. The average frequency of colours for these two stars is 

 given separately, A in rainy weather, and B in dry weather, 

 from a total number of 267 observations of Capella and 1 16 

 observations of Pollux. 



Intensity. Red. Orange. Yellow. Green, '^''bfuef'* Blue. Violet. 

 A ... 88 281 88 280 86 7 ' 250 8 

 B ... 63 299 41 304 122 26 194 14 



Average 76 290 65 292 104 17 222 11 



If we compare these results with the former ones we find the 

 frequency of red and particularly that of yellow to be consider- 

 ably greater in Capella and Pollux than in stars of the third type, 

 while the frequency of orange is very much less, having decreased 

 from 204 to 65. The influence of the weather was equally appa- 

 rent in these stars ; in dry weather red was more frequent, and 

 in rainy weather blue. The relative values of green and violet 

 are greater in these two stars than in the fifteen stars of the third 

 type ; probably these colours will become more important when 

 the observations are extended in a larger measure to the stars of 

 the two first types. 



It is therefore proved beyond doubt, by the results above men- 

 tioned, that the changes of colour which characterise the scintil- 

 lation of stars, are suljject to general laws which are quite as 

 regular and fixed as those which govern the changes in the 

 intensity of the phenomenon as we pass from one type to another, 

 or under the influence of rain and fine weather. 



In one of the last numbers of the Bulletin of the Brussels Royal 

 Academy of Sciences M. Montigny publishes the results of some 

 researches concerning the influence of the aiurora borealis on the 

 scintillation of stars. We may return to this subject at a future 

 date. 



NOTES FROM NEW ZEALAND 



A/TR. T. H. POTTS, of Ohinitahi, N.Z., sends us the 

 •^'■*- following notes : — 



Which Species 0/ Finns have Cones really Sessile f — In working 

 up the habits of a collection of pines one has felt a difficulty in 

 understanding why certain cones should be termed sessile ; for 

 example, the cone of P. tuberculata is described by Gordon in his 

 "Pinetum;" also by Broun, in his "Forester," as "quite 

 sessile." Why? Can such a description be correct at its early 

 stage of life ? It is then perched on a scaly foot-stalk, well 

 developed ; months elapse, its increasing bulk is protected with 

 needle-pointed scales, its foot-stalk becomes curved, but is 

 plainly visible ; the mature cone, grey and glossy, clings tightly 

 to its stem, it can scarcely be removed therefrom without tearing 

 off a shell of bark adhering to the nasal scales ; when wrenched 

 off it shows a portion of its curved foot-stalk that has been 

 embedded in the growing stem. 



A very similar habit may be observed in P. insignis. Should 

 not the cones of P. tuberculata and those of other species showing 

 a similar habit, be described rather as apparently sessile than as 

 "quite sessile " ? 



It may be mentioned that here P. tuberculata bears cones 

 not only on the stem and main branches, but also on the soft 

 green shoots of the outer branches, this would in part account for 

 the foot-stalks becoming embedded in the growing bulk of the 

 shoot. 



P. insignis here bears cones of longer dimensions than those 

 given by the authors before named ; five specimens measiure 

 rather over seven inches in lengfth, with a circumference of eleven 

 inches. 



Heredity. — One of my sons returning from a visit to the 

 Chatham Isles, brought back with him a young pup of a famous 



colly breed. As soon as it was grown enough to run about it 

 displayed an unusual excitement in the presence of horses by 

 jumping upwards repeatedly towards their heads. As this triek 

 or vice was unknown or unpractised by any of our dogs, it was, 

 of course, soon remarked. On inquiry of a Chatham Island 

 settler, I found this was a common trick in the colly family 

 " Bell " sprang from j so Bell faithfully held to the habits of her 

 race. 



UNIVERSITY AND EDUCATIONAL 

 INTELLIGENCE 



The following programme of the Natural Science Courses in 

 Trinity College, Dublin, may be of interest to our readers : — 

 In the Junior Sophister year natural science is represented by 

 two courses — one in zoology, the other in botany. Students 

 attending a course of lectures in natural science are examined 

 three times during the term on the subjects of the lectures, and 

 no student is allowed credit for his attendance who does not 

 answer sufficiently. In the Senior Sophister year natural 

 science is represented by one course in geology. In each term 

 examinations are held of those students in the Junior and Senior 

 Sophister classes who are qualified to become candidates for 

 honours. At the Michaelmas examination in the Junior Sophister 

 year prizes of 4/. and of 2/. are awarded by the Board, on the 

 recommendation of the Honour Examiners, to the best answerers 

 among the candidates. At the Hilary and Trinity examinations 

 of the Junior and Senior Sophister years honours without prizes 

 are awarded — of which honours there are two ranks. At the 

 Michaelmas examination of the Senior Sophister year, examina- 

 tions for Moderatorships are held. The Senior Moderators 

 receive gold medals, and the Junior Moderators silver medals, 

 which are given to them publicly before the University, by the 

 Chancellor, at the commencements, when they are admitted to 

 their degrees. The First Senior Moderator receives a large gold 

 medal if specially recommended by the Court of Examiners. 

 The subjects of examination for the Moderatorships in natural 

 science are the following, each of which has equal weight : — 

 I. Physical Geography, Geology, and Paleontology. All the 

 ordinary and honour coiurses of the Sophister years. A limited 

 course to be announced each year. Course for 1879 : — The 

 Silurian Period, 2. General and Physiological Anatomy. A 

 limited course to be announced each year. Course for 1879 : — 

 Circulation and Respiration. The Circulatory and Respiratory 

 Organs in Mammals. The Respiration and Assimilation in 

 Plants. 3. Zoology and Botany. All the ordinary and honour 

 courses of the Sophister years. A limited course to be announced 

 each year. Zoological Course for 1879 : — The Non-PlacentaJ 

 Mammals. Botanical Coiurse for 1879 '• — The Fucoids. The 

 Professors of Zoology, Botany, and Geology, give each a course 

 of demonstrations and a course of lectures in each term, espe- 

 cially meant for Junior Sophisters. The Museum of Compara- 

 tive Anatomy and Zoology is open, under the superintendence 

 of the professor, to all students, to whom every facility is given 

 for the prosecution of their studies. For the purposes of study 

 fresh specimen of plants are, under the superintendence of the 

 professor, to be had by the student from Mr. Frederick Moore, 

 at the College Botanical Gardens, at Lansdowne Road ; and a 

 large number of mounted specimens of cryptogamic plants are 

 also to be seen and examined in the herbarium. The Museum 

 of Geology and Palaeontology is open to the students attending 

 the course. 



The Science and Art School of St. Thomas' Charterhouse 

 Institution, Goswell Road (the largest in the United Kingdom), 

 under the direction of the vice-chairman of the London School 

 Board, commenced a new term on Monday evening the 6th inst. 

 Since the commencement of the present session upwards of 600 

 of our elementary school teachers of London have taken advan- 

 tage of the privileges offered by the classes. The attendance at 

 the classes for experimental work in chemistry and physics has 

 been very large. 



SCIENTIFIC SERIALS 



Journal of the Franklin Institute, November, 1878. — Some 

 time ago Prof. Thurston invented apparatus for re-determining 

 the coefficients of friction of lubricated surfaces, and the laws 

 governing such friction, for a wide range of temperatures, pres- 

 sures, and velocities. The machines have been in use about five 



