90 



NATURE 



also supplied them with materials for nets, mats, and 

 slings with w^hich they killed water-fowl, using for the 

 purpose of fishing canoe-shaped rafts of the tule. The 

 materials for the study of this civilisation now extinct 

 are found in the ancient village sites which have been 

 carefully examined by Mr. Barrett. The greater part of 

 Iiis elaborate report is occupied by a survey of the tribal 

 dialects, which adds largely to the information recorded 

 by .Schoolcraft, Powell, Bancroft, and others. In another 

 and less elaborate report Messrs. .S. .A. Barrett and A. L. 

 Kroeber give an account of the Miwok tribe. 



Of more general interest and importance is the investi- 

 gation conducted by Mr. W. J. Sinclair into the question 

 of the existence of relics of prehistoric man in the 

 auriferous gravels of the Sierra Nevada. The evidence of 

 the early existence of man in California has been hitherto 

 almost entirely based on the well-known report issued in 

 1880 by Prof. J. D. Whitnev in the course of the geo- 

 logical survey of the State. The present inquiry has been 

 devoted to a further investigation of the sites from which 

 the human remains and objects alleged to be the work 

 of man are said to have been derived. The result is 

 seriously disconcerting to those who have relied on the 

 evidence collected by Whitney. Mr. Sinclair points out 

 that, though these gravels and the intercalated volcanic 

 outflows are admittedly of various geological periods, 

 Whitney made no attempt to indicate from which series 

 of gravels the relics were obtained. In the case of the 

 discoveries made in mines worked by hydraulic machinery 

 the provenance of the vast majority of objects can no 

 longer be verified, and there is good reason to suspect 

 that many, if not all, the specimens have been washed 

 dow^n from modern Indian village sites situated on bluffs 

 overhanging the pits, which were disintegrated by the 

 powerful water currents. Mr. Sinclair reviews in detail 

 al' the more remarkable " finds " in this region. One 

 large mortar is said to have been found in association 

 with " a small oval tablet of dark coloured slate with 

 a melon and leaf carved in bas-relief." But it exhibits 

 no signs of wear from gravel friction ; the scratches are 

 all recent defacements, and the carving is said to show 

 very evident traces of a steel knife-blade. 



Special attention is naturally given to the Calaveras 

 skull immortalised by Bret Harte, which is now a 

 cherished possession of the Harvard Museum. Mr. 

 Sinclair asserts that the substance adhering to it is not a 

 gravel, but a cave breccia, and that the skull was not 

 obtained in the gravels beneath the rhyolite, or from any 

 other gravel of the rhyolitic epoch, none of which exhibit's 

 any trace of the stalagmitic cementation which has been 

 recognised in the skull matrix. He suggests that the 

 skull was derived from a comparativelv modern Indian 

 cave interment. If, he adds, man of a fairly high 

 developed type was in existence during the deposition of 

 these graveis, he must have been " a contemporary of the 

 three-toed horse and other primitive forms of the late 

 Miocene and early Pliocene, a thesis to which all geo- 

 logical and biological evidence is opposed." His con- 

 clusion is that the evidence is insufficient ta prove the 

 presence of the remains of men in the auriferous gravels ; 

 that there have been abundant opportunities for such relics 

 to be accidentally mixed with these gravels ; and that the 

 local geological conditions render it improbable that such 

 implements and bones have been found in the assumed 

 sites. 



It would be premature to attempt to criticise this 

 important report in detail. Doubtless those authorities 

 who assert the genuineness of these relics will not allow 

 the case to go by default. English anthropologists have 

 always adopted an attitude of reserve in relation to the 

 Calaveras skull. If the question of the antiquity of the 

 human race depended on the authenticity of these Cali- 

 fornian discoveries, the position would perh.ips be serious. 

 But even if Mr. Sinclair's indictment survives the criticism 

 to which it is inevitable that it must be exposed, the 

 abundant evidence from other unquestioned sources which 

 now exists renders a challenge of one set of relics a matter 

 of little importance. Whatever may be the result of the 

 controversy, the necessity of caution in dealing with 

 evidence which has been collected without rigid scientific 

 supervision is sufficiently obvious. 



NO. 201,-;, VOL. 78] 



x/- 



[May 28, 1908 



METEORIC PHENOMENA IN JUNE. 

 T N June there are few meteors seen which leave streaks. 

 Possibly the twilight is responsible for this ; it must 

 partially be so, but I do not think that it will wholly 

 account for the seeming rarity of meteors of the same type 

 as the August Perseids or November Leonids. 



Vet there are a few noticed by vigilant observers, and 

 especially in the morning hours. These are directed from 

 radiants in Pisces, .Andromeda, Aries, Perseus, and other 

 constellations in the same general region of the sky. 

 There are the a-^ Perseids, 5 Cassiopeids, jr, /i, and 7 

 Andromedids, /8 Triangulids, a Arietids, /3 and € Piscids, 

 and many others. In 1887 I saw several fine streak-leaving 

 meteors from a radiant near the position of the August 

 Perseids at about v Persei. All the centres referred to, 

 however, stand in need of corroboration, as they are sup- 

 ported on very slender evidence indeed. 



Fireballs are not uncommon to June, though few real 

 paths appear to have been hitherto determined in this 

 month. 



When we have such excellent atmospheric conditions as 

 prevailed in June, 1S87, it is possible to discern a large 

 number of showers. Some of these are directed from places 

 south of the equator ; for instance, there are radiants at 

 252°-21°, 269°-24°, 283°-I3°, 3os°-i2°, &-c. 



Occasionally there are some late Virginids and Serpentids 

 noticed in June, and a sprinkling of Ursa Majorids will 

 be recorded by the careful observer. 



The weather usually prevailing is excellent, and the sky, 

 though light, is attractive. The writer has often been 

 struck with the prominent aspect of the Milky Way on 

 midsummer nights. It stretches nearly overhead, and the 

 rich regions in Cassiopeia, Cepheus, and Cygnus are often 

 beautifully displayed at this season of the year, notwith- 

 standing the lack of suitable darkness. 



W. F. Denning. 



VISION AND COLOUR-VISION. 



'T'HE difference in physiological effect between incident 

 and reflected light is a commonplace to those who 

 have investigated the influence of surroundings on sensitive 

 animals. The influence du fond is a function of the 

 altered light reflected from these surroundings upon the 

 eyes or skin of animals capable of assuming variable 

 coloration. The direct incident light has little or no effect 

 in producing the result. 



In a series of papers (Zeit. f. Augenheilkundc. Bd. xvi., 

 pp. 448-463 ; Wiener medczinische Wochcnschrifl, No. 46, 

 1906, No. 48, 1907) Prof. Raehlmann asserts that the light 

 perceived by vertebrates is reflected from the plane 

 separating the outer laminated limb of the rods and cones 

 into the inner homogeneous limb of the same. He now 

 claims that colour-vision is due to the reflected light 

 setting up " stationary waves " in the inner limb of these 

 retinal elements. To support this view he proceeds to 

 show from recent work that if a Lippmann gelatin film 

 (placed between a mirror and a source of light) be exposed 

 to different parts of the spectrum, and then cut into micro- 

 scopic sections and examined under a high power, the 

 substance of the film is seen to be traversed by zones of 

 black granules separated by iroloui-less intervals, the inter- 

 spaces equalling the w-ave-Iength of the light used, 

 and, therefore, whilst perceptible 'in the case of red and 

 yellow light, are so crowded together in green and blue 

 light as to be almost continuous. This result is claimed 

 by Prof. Raehlmann as confirmatory evidence of the truth 

 of his hypothesis. The sensitive film is represented by the 

 morphologically inner portion of the rod or cone, the 

 mirror by the membrane separating this from the outer 

 refractive portion, and the case would be complete if any 

 arrangement of black and colourless zones comparable to 

 that set up in the film could be discovered in the inner 

 portion of the cone, but though Prof. Raehlmann has used 

 the ultra-microscope after a given monochromatic ex- 

 posure, he can discover nothing in the inner cone-limb 

 but a perfectly uniform granulation, and though the length 

 of the cone is known to vary with that of the light-waves 

 used, vet he has not been able to correlate the somewhat 



