Sei'TEmbkk 29, 1910] 



NATURE 



Three out of five numbers of the Records of the Indian 

 Museum, recently to hand, contain articles on biting flies 

 and gnats. In the first of these, vol. i"., No. i, Mr. 

 1'". V. Theobald describes certain new genera and species 

 of Culicida.", typified by specimens in the Indian Museum. 

 It is stated, however, that in the case of the Culices with 

 banded proboscis, some at least of the determinations must 

 be regarded as provisional, since certainty cannot be 

 attained until both sexes have been bred in captivity and 

 the generative organs of the males and the larvae carefully 

 e.\amined. In No. 3 of the same volume Mr. E. Brunetti 

 records a protest against what he considers unnecessary' 

 subdivision and splitting in the Culicidae, remarking that 

 specialists in the Diptera must regard the present state of 

 affairs as absurd, and that Prof. W'illiston appears to be 

 the only systematic diplerologist who has attempted to 

 stem the tide. The plea of the unwieldiness of big genera 

 cannot be upheld, it is added, since the systematist is 

 quite accustomed to such genera : a similar protest, it may 

 be mentioned, seems called for in the case of the excessive 

 generic splitting now in vogue in the squirrel and mice 

 family. Mr. Brunetti concludes by stating that the sub- 

 ject will be more fully discussed in the supplement to the 

 catalogue on which he is now engaged. 



\n article forming part ii. of the fourth volume, by Dr. 

 Annandale, on Indian sand-flies (Phlebotomus), will be 

 read with interest, since not only are these minute insects 

 some of the greatest torments to Europeans in India, but, 

 as may be inferred from the investigations made on their 

 south European representatives, it is practically certain 

 that they are also carriers of certain types of fever. 



Finally, in the fourth and last part of vol. iv., Mr. 

 Brunetti publishes a systematic revision of the Oriental 

 blood-suckmg flies of the family Muscidie, with the 

 description of a new genus. 



From among a dozen articles in the first and second 

 parts of the fifth volume of the Records, it must suffice 

 to direct attention to one by Dr. R. E. Lloyd, on variation 

 in Indian rats. In a previous paper the author has 

 adduced evidence in favour of discontinuous variation 

 having played a prominent part in the production of races. 

 Individual rats from any particular towns, for instance, 

 sometimes show more or less marked differences from their 

 fellows, and the evidence they afford for discontinuous 

 evolution lies in the manner in which these are distributed 

 among the multitude of whole-coloured specimens. In the 

 present paper it is stated that, among the thousands of 

 normally coloured rats infesting Poona, there is found a 

 colony of about one hundred individuals characterised bv 

 the presence of a white breast-patch, these having appar- 

 ently originated in the city itself. Again, it was found 

 that the rats of Naini Tal differ from the normal type of 

 plains-rat by their sliorter tails, longer and greyer fur, 

 and a more or less well-defined white breast-patch. Some 

 rats in the district differ, however, from this tvpe by the 

 under side of the tail being white. .Accordingly, we find 

 that in a single limited area there live, under apparently 

 similar conditions, two phases of a widely distributed 

 species, differing from one another solelv in one obvious 

 feature, these two phases living apart from each other. 

 Obviously, any explanation as to the origin of the while- 

 tailed phase will apply equally to the case of the white- 

 breasted Poona rats, and the author concludes bv 

 endeavouring to explain each instance by the light of the 

 theory of gametic factors. R. L. 



THE BRITISH ASSOCIA TION A T SHEFFIELD- 



SECTION G. 



engineering. 



Opening .Address by Prof. W. E. D.^lbv, M..^., 



M.Inst.C.E., President of the Section. 



Biitish Railways: Some Facts and a Few Problems. 



It is remarkable how few among us really realise the 

 large part that railways play in our national life. How 

 many of us realise that the capital invested in the rail- 

 way companies of the United Kingdom is nearly twice 

 the amount of the national debt ; that the gross income 

 of the railway companies is witliin measurable distance 



NO. 2135, VOL. 84] 



of the national income ; that to produce this income every 

 inhabitant of the British Islands would have to. pay 

 annually 3/. per head; that they employ more than six 

 hundred thousand people ; and that about eight million 

 tons of coal are burnt annually in the fire-boxes of their 

 locomotives? I hope to place before you in the short 

 time which can be devoted to a presidential address a 

 few facts concerning this great asset of our national life 

 and some problems connected with the recent develop- 

 ments of railway working — problems brought into exist- 

 ence by the steady progress of scientific discovery and the 

 endeavour to apply the new discoveries to improve the 

 service and to increase the comfort of the travelling 

 public. 



A great deal of interesting information is to be found 

 in the Railway Returns issued by the Board of Trade. I 

 have plotted some of the figures given, in order to show 

 generally the progress which has been made through the 

 years, and at the same time to exhibit the rates of change 

 of various quantities in comparison with one another. 



Consider, in the first place, what the railways have 

 cost the nation. This is represented financially at any 

 instant by the paid-up capital of the companies. The 

 total paid-up capital in 1850 was 240 millions sterling. 

 In 1908 this amount had increased to 1310 millions. The 

 curve marked " Total "in Fig. i shows the total paid-up 

 capital plotted against the year. It will be noticed that 



the increase per annum is remarkably regular up to about 

 1896, and is at the rate of not quite 100 millions per 

 annum. After this date the capital increases at a some- 

 what greater rate, but in 1900 the rate drops with a 

 tendency to a gradually decreasing value. Part of the 

 increase immediately after 1896 is, however, due to 

 nominal additions to the capital. The extent to which 

 this process of watering the stock has been carried is 

 indicated over the period 1898 to 1908 by the curve AB. 

 In the year 1908 the nominal additions to capital amounted 

 to 196 millions of pounds. 



Curves are also plotted showing the amounts of the 

 different kinds of stock making up the total. It will be 

 noticed that the ordinary stock is a little more than one- 

 third of the total paid-up capital in igo8, viz. 38 per cent. 

 In 1870 it was about 43 per cent. 



The lower curve on the diagram sho%vs the gross 

 receipts, which amounted to 120 millions of pounds in 

 1908. The dotted line indicates the net revenue after 

 deductin'g from the total receipts the working expenditure. 

 This, for 1908, was 435 millions, corresponding to 3'32 per 

 cent, of the total paid-up capital. If the net receipts are 

 reckoned as a percentage of the paid-up capital after 

 deducting the nominal additions, the return is increased 

 to 39 per cent. These figures practically represent the 

 average dividend reckoned in the two ways for the year 



