6io 



NATURE 



\_April 29, 1880 



Prof. Alex. Agassiz must have strangely misread that 'para- 

 graph in my leclure in which I refer to the two deepest soundings 

 of the Tuscarora if he supposes that I intended to cast any doubt 

 upon their trustworthiness as indicating '* depths considerably 

 exceeding 4,000 fathoms." In the Official Report, now before 

 me, these two soundings are thus recorded 1 — 



" No. 15 : 4,643 fathoms. No specimen (of bottom). Wire 

 broke. Bottom not reached. 



*' No. 33 : 4,655 fathoms. No specimen. Wire broke." 



As there is no mention in the second case of the wire having 

 broken in reeling-in (which is stated in several other cases), and 

 as the length of wire run out corresponded almost exactly with 

 that run out in the first, it was not unnatural that I should sup- 

 pose that the wire broke by its own weight without reaching 

 bottom. But I expressly cited these two soundings, incomplete 

 though they were (no specimen of bottom having been brought 

 up), as evidence in support of my case that those " gigantic pit- 

 holes," in which extraordinary depths have been encountered, 

 occur in regions of great Volcanic activity. 



56, Regent's Park Road, William B. Carpenter 



N.W., April 27 



Seeing by Electricity 



With respect to the letter of Messrs. Ayrton and Perry 

 (Nature, vol. xxi. p. 5S9), in which they propose to utilise for 

 this purpose Dr. Kerr's discovery of the rotation of the plane of 

 polarisation of light reflected from the pole of a magnet, will 

 you allow me to give you some details of a repetition of Dr. 

 Kerr's experiment which I made a year or two ago. 



I used an electromagnet consisting of an iron bar 2 feet 4 

 inches long and 2\ inches diameter, surrounded by 70 lbs. of 

 wire, and excited by ten Grove cells. 



The total double rotation produced, not by slightly altering the 

 resistance, but by reversing the current, was never more than 26' 

 (twenty-six minutes of arc). 



To see this at all with a very delicate Jellett analyser, it was 

 necessary for the observer to increase the sensitiveness of his eye 

 by sitiing in total darkness for some ten minutes before each 

 observation. 



Your readers can judge what chance of obtaining visible 

 changes of illumination there would be with " little " magnets 

 and mere variations in a current not powerful enough to fuse a 

 selenium resistance. J. E. H. GORDON 



32, Elvaston Place, Queen's Gate, S.W., April 22 



Ophiolepis mirabilis 

 The statement concerning Prof. Martin Duncan's Ophiolepis 

 mirabilis contained in the review of Prof. Lyman's account of 

 the Challenger Ophiurans was not intended to represent an 

 expression of opinion of the Reviewer upon the matter, but 

 simply the conclusions of Prof. Lyman as expressed in the 

 memoir under review. The matter was not cited as a question 

 of mistake, but of difference of opinion between two experts. Prof. 

 Lyman enters, in the memoir referred to, at some length into his 

 reasons for considering Prof. Duncan's species, as described, to 

 be a true Ophiopholis. This latter genus Prof. Lyman thinks 

 quite remote from Ophiolepis, in spite of the evidence adduced 

 by Prof. Duncan. I am sorry that I did not make it clear that 

 I was citing Prof. Lyman's opinion and not expressing any 

 judgment of my own. The Reviewer in Question 



The Omori Shell-Heaps 



Desiring as much as possible to save space and avoid rhetoric, 

 I shall be content to reply to the pith of Prof. Morse's amusing 

 diatribe contained in Nature, vol. xxi. p. 501, principally by 

 citing extracts from a recent paper on Prehistoric Remains in 

 Japan, read by Prof. Milne before the Asiatic Society of Japan, 

 and printed, together with a report of the discussion it gave rise 

 to, in their Transactions, published in February last, which I 

 received about a fortnight ago. 



The main object of my note in Nature, vol. xxi. p. 350, was 

 to show that the antiquity claimed by Prof. Morse for the Omori 

 mounds was not warranted by the facts. In this view I am sup- 

 ported by Prof. Milne, Dr. Faulds, and Mr. Aston, whose united 

 authority I venture to prefer to that of the Salem zoologist. 



Prof. Milne examined a number of shell-mounds in various 

 parts of Japan, both in Yezo, where the Aino race still flourishes, 



and in the main island, including the Omori heaps, but he does 

 not mention having met with any human remains in any of Ihem. 

 Adverting to Prof. Morse's conclusions from his examination of 

 the Omori shells, which may be briefly presented thus : — 



That changes have taken place in the relative abundance, size, 

 and proportions of certain species and in the extinction of certain 

 species, 



Prof. Milne quotes from the Memoir : " The modification in the 

 relative size, &c, is profound, and seems to indicate" either a 

 shorter period of species-variation than is commonly admitted, 

 " or else that the deposits presenting these peculiarities have a 

 much higher antiquity than had before been accorded them." 

 Prof. Milne (but then he is merely a "Briton in Japan," and 

 qui such disposed, doubtless, in the eyes of Prof. Morse, 

 to sneer at everything Japanese, shell-mounds included) is 

 inclined to think these modifications "in great measure due to 

 the great changes which have been taking place in Yedo 

 Bay during recent limes." The italics are Prof. Milne's. 

 ". . . The bay is rapidly silting up. . . during the last 800 

 years large cities have sprung up round its shores, all of which 

 have added something to destroy the purity of its shallower 

 waters. All these causes combined are and have been making 

 changes in physical conditions, and with them we should 

 naturally expect a rapid change in the faunas which are dependent 

 on them." Further on a map is given showing the ancient coast 

 lines at and near Yedo, and proving the magnitude and rapidity 

 of the various successive encroachments of the shores upon the 

 waters of the bay. 



Again, " The conclusion to which I am led with regard to the 

 shell-heaps is that they are of Aino origin . . . the positions 

 which these shell-heaps occupy are on spots which we know . . . 

 were once tenanted by Ainos, and even down to the end of the 

 twelfth century Ainos were living in Nipon." By Nipon is 

 meant, I presume, the main island. I may add that I have often 

 heard from Japanese of Aino colonies still existing in the north- 

 eastern districts of the main island, but not distinguishable by 

 language, or customs, or otherwise than physically from their 

 Japanese neighbours. The average advancement of the land at 

 and near Yedo, Prof. Milne states as varying from 3S feet to 

 2 feet per annum, which would account for the present distance 

 of the Omori, heap from the shore being attained in from some- 

 thing under 100 to something over 1,000 years. Mr. Aston, in 

 the course of the discussion which followed the reading of Prof. 

 Milne's paper — I quote from the report in the Transactions — 

 "was glad to observe a tendency to diminish the antiquity 

 which had been earlier assigned to these remains (from Omori) 

 by some of the writers on the subject. Civilisation in Japan is 

 a product of much more recent growth than in Europe, and we 

 do not require to go so far back in order to meet with tokens of 

 a primitive degree of advancement." Mr. Aston then showed 

 that in the middle of the eighth century a large portion of the 

 main island was exclusively Aino. Dr. Faulds assigned " 600 

 years as the probable antiquity of the Omori heap," and Prof. 

 Milne in reply said that the rise of land variously evidenced 

 round Yedo Bay, " taken in conjunction with the vast deposits 

 of silt which are brought down by the various large rivers which 

 flow into the bay, would make the changes in coast-line exceed- 

 ingly rapid. " 



With regard to the pottery of the Omori heaps, Prof. Milne 

 says : " The designs are in very many instances similar to the 

 designs which are carved by the Ainos of the present day." 

 On this point Dr. Faulds's testimony is more emphatic. "The 

 'mat' impressions figured by .Prof. Morse in Plate V. Fig. I, 

 are to be found repeated in the most recent pottery ; " the 

 types of pottery in the shell-heaps did not seem " to be separated 

 by any one well -marked character from contemporary pottery of 

 a low grade. The shell-heaps scattered along the old and recent 

 coasts of Yedo Bay presented in their fragments of pottery a 

 series of modifications leading up to recent times, and some of 

 the heaps may be seen in actual process of accumulation." 

 Further, Mr. Ninagawa of the Tokio Museum, the principal 

 authority on the subject of Japanese pottery, decides that the 

 "remains . . . cannot be older than 1,000 years." Dr. Faulds 

 showed some coarse pottery of the day not dissimilar to that of 

 the shell-heaps, and was not even prepared "to accept finally 

 the belief that the Ainos were the founders of these heaps." 



From personal investigation of many remains of shell-heaps 

 on the coast-line and inland between Yedo and Yokosuka, I can 

 corroborate Dr. Faulds's statement. I do, however, believe 

 that the heaps at Omori were the handiwork of Ainos, very 



