Feb. 19, 1880] 



NATURE 



37i 



This immediately suggests the following construction : — 

 Take O G = C, and with this as radius, descril e a semicircle. 

 Draw any radius O A, then take A B perpendicular to O \\ and 

 j?./' perpendicular to A : then P is a point on the required 

 curve. Because 



OB= OA.cos OAB 



= O A sin 9, where 9 = angle A X. 



Also O P = B sin 9 

 = OA an* ft 



Therefore P is a point on the curve. 

 1 



In a similar manner any number of points on the curve may 

 be obtained ; and by varying the length G, we get different 

 curves of the same class. 



Near to the point G in the figure, the points on the curve 

 cannot be constructed accurately by the method just given ; but 

 it the radius of curvature for the point (.r = o) be calculated, it 

 will be found that for the point G it is 2-S Q is the centre 

 of curvature. And a large arc of the circle' described about O 

 with radius Q G coincides with the curie. Thus the whole 

 curve may be constructed w ith great accuracy. 



From equation (1) radius of curvature at any roint (x lA is 

 given by ' r x f* 



C.yi^x- + y ')i 



3 (2*»+jr*)(*« +/-) 



or, with x eliminated by (1), 



p=T Cl.yl.UC* - 3M 

 3{ad -/<) 



Thus )■ = "432 C gives the point of maximum radius of curva 

 ture. 

 Lir.es of force — 



y 



These curves may be obtained by giving to C the values 

 C=0(J., 

 C= OG„ 



c = . 

 c = oc t . 



The points (.F; are points of r.-.inimu:n curvature. 



Glasgow, January 29 



John BUCHANAN 



Prehistoric Man in Japan 



In an article on this subject (Nature, vol. xxi. p. 350) by Mr. 

 %■"■ Dickins, there is a mistake in dates. He says: "The 

 ' adzuma ' or eastern region of the main island was probably 

 peopled chiefly by an Aino race, up to the fourteenth or fifteenth 

 centuries." He hesitates to assign a higher antiquity to the 

 Omon heaps (which were discovered by Prof. Morse) than the 

 thirteenth or fourteenth century, and yet thinks it probable that 

 they were the works of an Aino race. But the fact is that this 

 part of the island was already inhabited by the present race, who 

 had expelled the Ainos long before those periods. Consequently 

 if, as he thinks, the heaps were the remains of the thirteenth or 

 fourteenth century, they cannot be the works of the Ainos ; if, 

 on the other hand, they were the works of the Ainos, a much 

 higher antiquity ought to be assigned to them. Such being the 

 case, either one of his conclusions must be incorrect. 



Lond ' -'" S. SUGIURA 



Monkeys in the West Indies 

 In Nature, vol. xxi. p. 131, there is a letter from Mr. 

 Edmund Watt, of Dominica, calling in question the correctness 

 of Prof. Mivart's statement in his paper on " TaiN," regarding 

 the non-exi-.tence of monkeys in the V est Indies. 



If by this statement Prof. Mivart means that monkeys are not 

 to be found wild at the present time in any of the West India 

 islands, it is certainly incorrect, as they abound in St. Christopher 

 and Nevis. 



If, on the contrary, and what is much more pro! able, he 

 means that monkeys are not native in any of these islands, then 

 he has made no mistake, as I think I shall be able to show. 



It certainly does appear remarkable that no species of monkey 

 should exist in the wild state in any of these islands along the 

 whole range from Grenada to Jamaica, with the exception of St. 

 Christopher and Nevis, and the question that naturally presents 

 itself is, Have they been introduced ? I am not aware that there 

 is any tradition to this effect in either of these colonies. 



It appeared to me that the most likely mode of obtaining in- 

 formation on this point would be to examine all the old West 

 India histories in my possession, as those writers who treated of 

 the natural history of the islands could not fail to notice so 

 singular a fact as the existence of monkeys in two neighbouring 

 islands and in none of the others. The first history examined 

 was that of Rochefort, "Hi hire Naturelle et Morale des 

 Antilles, 1665." He names and describes all the mammalia in 

 the West Indies known to him, but no mention whatever is made 

 of monkeys. The next work examined was the " Histoire 

 Generate des Antilles," by Tere Du Tertre, 1667, a m o t inte- 

 resting book, but little known. Du Tertre was a man of keen 

 observation, and be has devoted a large portion of his work to 

 natural history- He gives a very clear description of all the 

 mammalia w ith which he was acquainted, but there is nc t a 

 word about monkeys. This is the more notable from the fact 

 that St. Christopher was considered the mother colony of the 

 other French settlements, and Du Tertre lived there for several 

 years, and visited the island frequently. From the negative 

 evidence afforded by Rochefort and Du Tertre, it may be con- 

 cluded that monkeys did not then exist in these islands, and, in 

 consequence, must have been subsequently introduced. 



On examining a third historical work on the West Indies, that 

 of I'ere Labat, "Ncuveau Voyage aux Antilles, 1744," conclu- 

 sive evidence was discovered of the when and the Iny.u of the 

 importation of the monkey family into St. Christopher. 



Father Labat says that he paid a visit to St. Christopher in 

 the year 1700. He describes the French quarter, the island 

 being inhabited at the time by French and English, and gives a 

 very amusing account of a monkey hunt (chaste des singes). He 

 makes the following statement regarding the introduction of 

 monkeys into the island, which I give in the original. "Pendant 

 que les Anglais ctoient demeurez maitres des terres des Francois, 

 dont la plus grande partie resterent en friche, les singes qui 

 s'etoient e'ehapez des maisons des Francois pendant la guerre, 

 multiplierent tcllement que quand on reprit possession de ITsle 

 en les voyoit par gros-es troupes. Us venoient voler jusques 

 dans les maist ns, & lorsqu'on plantoit des Cannes, des patates 

 ou autres choses, il falloit y faire sentinelle jour and nuit, si on 

 v iiiloit que ces animaux n'emportassent pas tout ce qu'en avoit 

 mis en terre." 



It is thus made clear that the existence of monkeys in St. 



