130 



NATURE 



[Bee. 17, 1874 



viduals who compose the mass, each one being repre- 

 sented by a dot. His diagram, adapted in (<?) of the 

 present figure, stands for a population descended from a 

 common ancestral stock, the individuals congregating 

 most closely about the place of the central type or 

 standard individual, and gradually decreasing in numbers 

 as they become more different from that type or standard. 

 In this graphic representation, the race can, of course, 

 only be arranged in order as to some one quality. In the 

 particular case for which Mr. Galton uses it, this quality 

 is stature. The individuals of the mean or average height 

 (say, 5 ft. 8 in.) are shown as most crowded, while the 

 taller and shorter men become fewsr and fewer as their 

 stature becomes more unusual, till at last we come to one 

 or two outlying giants and dwarfs, beyond whom no more 

 individuals exist. Here, then, is set before us the dis- 

 tinctest idea of a race, both as to its type and as to its 

 limits of variation on either side. I now proceed to apply 

 the method of this diagram to a more complex state of 

 things. 



In nature we habitually find races blending into one 

 another. Our own species shows this perfectly, when 

 mixed breeds are considered. Let a population partly of 

 Europeans and partly of negroes be placed on a West 

 Indian island. These two races being classified according 

 to colour, a few of the darkest Europeans would be seen 



to make some slight approach towards a few of the 

 lightest negroes ; but there would be no individual of 

 either race who could be mistaken for one of the other. 

 They would, therefore, at the outset be represented by 

 two such groups of dots as (a), with a blank space between. 

 But as soon as the first generation of mulattos come into 

 existence the case will be altered. An intermediate race 

 has arisen with its definite central type, and its variants 

 now coming much closer to the whites on one side and to 

 the blacks on the other. In the next generation there 

 will be quadroons and sambos (cross between negro and 

 mulatto, Spanish zanibo). Now the fusion will be so 

 complete, that of many individuals it will hardly be 

 possible to say whether they are quadroon or mulatto, 

 while in the same way others may be either mulatto 

 or sambo, or either sambo or negro. One or two rnore 

 generations would still further obliterate the distinc- 

 tion between a 1 joining varieties, but for convenience 

 sake the figure (/'), showing the blended races, is taken 

 only in the second generation. In this way the whole 

 human spocieB, or any species of plants or animals, may 

 be ideally classified into its various races, either in fact 

 blending into one another, or capable of so blending by 

 intercrossing. A species thus classified into its com- 

 ponent races is shown either in {b) or the central part 

 of {c). 



[a) 



W 



WHITES Q_UADflOONS MULATTOS 



SPECIES 



SPECIES 



aACE RACE 



RACE RACE 



Let us now attend to the effect of variation, artificial or 

 natural. Starting with a single race, this may in the 

 course of time and circumstance develope within itself a 

 number of varieties or races. Nor, if variation is pro- 

 moted either under domestication or by various conditions 

 of life acting for a long series of generations, is there any 

 difficulty in conceiving two adjacent varieties to recede 

 from one another and the intermediate individuals to die 

 out, till a wide gap is left between the two races. At first 

 this gap, though real, would be capable of being at any 

 time bridged over by cross-breeding, and thus would only 

 be a temporary break. But as variation went on, a critical 

 period would at last be reached, when individuals from 

 the two sides could no longer produce fertile offspring. 

 Then a scpr.ration of one species into two would have 

 taken place. This change is illustrated in (c), where the 

 extreme forms of two adjacent species are seen to the 

 right and lelt, still perceptibly near the extremes of the 

 original species from which they have parted, but never to 

 be joined to it again unless by a process of backward varia- 

 tion most unlikely to happen across any width of interval. 

 This ideal representation was at first intended rather to 

 show the actual distribution of animals in existing species 

 than to involve a hypothesis as to how these species origi- 

 nated. But, after consulting Mr. T. R. Stebbing, I see 

 the desirableness of making the diagram express both 

 facts and hypo'resis, leaving those who will to take them 



apart. The whole figure, as it stands, contains an ideal 

 of evolution or development from a single race of animals 

 at {a), into a species made up of several races at (/'), and 

 thence into any number of separate species at (c). 



Edward B. Tvlor 



TRANSIT OF VENUS 

 Colonel Tfiiiianf's Siaiwn at Roorkce, India. 

 'T^HE fuU and very able account of the preparations for 

 -'■ observing the Transit of Venus drawn up by Prof. 

 Forbes and published in these columns do not include 

 those which have been made by the Government of India 

 under the authority of the Secretary of State in Council. 

 When Prof. Foibes wrote, these were not sufficiently 

 advanced to admit of description. Now tliat they are 

 completed it is desirable that an account of them should 

 be made public. 



At an early period Col. J. F. Tennant, R.E., F.R.S., 

 brought the subject before the Viceroy in India, and pro- 

 posed the organisation of a station in the north-west, 

 near Roorkee, well known as the seat of the great Civil 

 Engineering College. The Viceroy heartily responded to 

 the suggestion, and communicated his views to the Home 

 Government. 



Some time was unfortunately lo'^t in official correspond- 



