May 4, 1SS3.] 



SCIENCE. 



359 



a scries of independent figures, designed to show the 

 degive of development attained by each type at any 

 epocli reliUively to other epoulis. 



Tlic'Se cli;u-|s uiid diasrams were thoroughly dis- 

 cussed; and I lie li'cl.ure closed with a few remarks on 

 the genealogy of plants, illustrated by an arborescent 

 figure showing one of the possible ways ii^ which the 

 present forms of plant-life may have been derived. 



LETTERS TO THE EDITOR. 



[Corrfffpondcvti are reqiteaied io he (la brirf as poasiiMe. The 

 wriitr^a name is in oit tasea required as proof 0/ good faitli.'\ 



Intelligence of the croTW. 



Japan is the birds' j>aradise, as fire-arras cannot 

 be carried except by special permit. Tbough their 

 punishment of criminals is sometimes extremely cruel, 

 to shout birds for sport or for scientilic purposes 

 would never enter the heads of this kind-hearted 

 people. I noticed, in many parts of the country, 

 that the crow felt a sense of security, meeting man 

 boldly, conscions that he is a benefactor — and ac- 

 knowledged as such — -by killing injurious grubs, 

 even though he collect a few grains of corn in the 

 operation. He scorns to lly at your approach, and 

 fears not a stick pointed at him, which he never 

 takes f..r a gun. He is as familiar in Japan as he is 

 shy in AmiMici and Europe. 



Another instance of this bird's intelligence came 

 under my observation as I was walking among the 

 crumbling arches of Caracalla's baths in Kome, in 

 April, 1SS2. When near the walls, a stone nearly as 

 large as my fist fell at my feet. Fearitig a recurrence 

 of what I supposed was an accident of perishing 

 masonry, our party went fartlier toward the centre of 

 the area. A second and a third fell near us; and, 

 looking up, I saw some crows circling alioye our 

 heads, one of wliich dropped a fouitli from hisclaws. 

 It seems that we h;id been strolling too near their 

 nests in the wall-; and they took this method to drive 

 ' us away. — a very effectual one, iis a stone of that 

 /Size, fading from the height of sixty feet, was an 

 exccTdingly (l,uii;erous missile, and perhaps only pre- 

 vented from being fatal by the failure of the bird to 

 make allowiuice for the impetus given by its own 

 motion. The aim was accurate, tuid the discharge 

 right overhead; but, as both we and the bird were 

 moving, it fortunately missed its mark. 



Samuel Kneeland. 



Paleolithic man in Ohio. 



In SciE>'CK of April \?>, p. 271, rrofessor Wright 

 remarks that "' no iialeolithie implements have as yet 

 been fomul [iu Ohio], but they may be confidently 

 looked for." It has seemed to me possible, from my 

 own siudii'S of the remains of paleolithic man in the 

 valley of the Delaware Hiver, that traces of his pres- 

 ence may only be found in those liver-valli'ys which 

 lead directly to llie Atlantic coast, and that paleolithic 

 man. was essentially a coast-ranger, and not a dweller 

 iu the interior of the continent. If we associate these 

 early people with the seal and walrus rather than with 

 the reindeer, and consider them essentially hunters of 

 these amphibious mammals rather than of the latter, 

 it is not incrcdihle. I submit that they did not wander 

 so far inland as Ohio, nor even so far as the eastern 

 slope of the AHeghanies; and we need not be sur- 

 prised if paleolitliie implements, concerning which 

 there can be no doubt wiiatever, — for recent Indians 

 made and Use<l stone implements that are 'paleo- 

 litliie' in character, — are not found in Ohio, or even 

 in Pennsylvania west of the valley of the Susque- 

 hanna Kiver. 



Unquestionable evidences of paleolithic man in 

 America have been found in the valleys of the Con- 

 necticut, Delaware, and Susquehanna Kivers, and 

 probable traces of the same people in the valleys of 

 the Hudson, Potomac, and .James Rivei's. This is an 

 extensive range of territory, and one not too limited 

 as the probalile area occupied by a primitive people. 



If we could .accept witliout qualification the asser- 

 tion occasionally made, that America's earliest race 

 was ]ire-glacial, tlie difficulties that beset the study 

 of paleolithic man would quickly vanish. I am dis- 

 posed to believe it, upon thcoietical grounds, but 

 have met with no satisfactory demonstration that 

 such was (he case. In a recent lecture before the 

 Franklin institute of Philadel])hi;i, Prof. H. Carvill 

 Lewis remarked, " That man existed before the gla- 

 cial epoch has been inferred from certain facts, but 

 not satisfactorily proven." 



Accepting the above conclusion, and coupling it 

 with the assertion made by both Professors Wright 

 and Lewis, tliat the melting of the great continental 

 glacier occurred so recently as ten thousand years 

 ago, we are compelled to crowd several momentous 

 facts iu American archeology into a comparatively 

 brief space of time; and it becomes nnn-e probable 

 that the fabricators of the implements found in post- 

 glacial gr.avels came from some tiansallantic conti- 

 nental area, and had not wandered far inland when 

 met by southern tribes, who drove thein northward, 

 exterminated or absorbed them. 



On the other hand, if the relationship of paleo- 

 lithic man and the Eskimo is not problematical, and 

 llie latter is of American origin, then I submit that 

 man was pre-glacial in America, was driven south- 

 ward by the eStension of the ice-sheet, and probably 

 voluntarily retreated with it to more northern re- 

 gions; ami, if so, then iu Ohio true pideolithic im- 

 plements will surely be found, and evidences of man's 

 pre-glacial age will ultimately be found in the once- 

 glaciated areas of our continent. 



Chas. C. Abbott. 



The copper-bearing rocks of Lake Superior. 



Mr. Selwyn's courteous reply in Sciexce, No. S, to 

 my letter in No. 5, calls for only a few remarks from 

 me. 



In his admission that I am right in asserting the 

 existence of a great unconformity iu the St. Croix 

 region, between the basal sandstones of the Missis- 

 sippi valley and the copper-bearing rocks, he, yields 

 the principal point for whicli I conteiul. It seems 

 very unreasonable to me to extend the term 'Cam- 

 brian' over this unconformity; but, in the absence 

 of any fossil evidence, I am relatively indifferent on 

 this point. I only insist on the complete distinctness 

 of the copper-bearing strata from tlie lowest sand- 

 stone of the Mississippi valley, and from the horizon- 

 tal sandstone of the eastern end of the south shore 

 of Lake Superior. Mr. Selwyn evidently does not 

 appreciate that the St. Croix valley unconformity is 

 not merely ' locally very great.' Our conclusions as 

 to this unconformity are not based on any one local 

 unconformable contact, but upon the fact, that, for a 

 distance of over fifty miles in a north-westerly to 

 south-easterly direction, the basal sandstone of the 

 Mississippi valley lies horizontally athwart the courses 

 of the tilted Keweenawan beds, overlying and bury- 

 ing the western termination of these beds, which are 

 here disposed in synclinal form. Nor is the St. Croix 

 Falls locality, described in the third vidume of the 

 Geology of VVisconsin, the only place in the St. Croix 

 valley where the unconformity may be actually seen. 

 Besides other i>laces, it may be finely seen on Snake 



