192 



SCIENCE. 



[Vol. XXI. No 531 



intended to withstaml heat have plumbago mixed in the inner 

 surface of the vessels. There are many fanciful designs of this 

 ware, some very large jars, pots of all shapes, bowls, cups, 

 pitchers, etc. Henry Hales. 



Eldgewood, N. J. 



The Sense of Boundary in Dogs. 



I HAVE followed with much interest the discussion in Science 

 caused by the recent communication of my friend, Dr. Hall, en- 

 titled " Is there a Sense of Direction ? " 



Dr. Hall's query recalls to my mind a striking example of ani- 

 mal intelligence which I witnessed in a dog, and of which I sent 

 a brief notice at the time to the London Spectator. 



Some eight years ago I was staying with friends who had a full- 

 blooded Irish deer-hound. On the adjoining estate lived a pointer. 

 Our dog was scarcely more than a year old, while our neighbor's dog 

 was quite well along in life. The dogs had never been friendly ; 

 indeed, from the first, the pointer manifested a decided aversion 

 to the young deer-hound. Whenever the old dog caught his 

 youthful neighbor trespassing be would immediately drive him 

 back over the boundary between the estates. Both dogs, even 

 when going at full speed, would invariablj' stop the moment our 

 dog had crossed the line. The two estates are virtually con- 

 tinuous, there being neither hedge nor fence separating Ihem. 

 The dividing line runs between two stone posts about a foot in 

 height and some two hundred feet apart. These posts, of the 

 existence of which I was quite unaware, until the singular be- 

 havior of the dogs called my attention to them, are in the sum- 

 mer time usually hidden by the grass, and in winter are often 

 buried under the snow. I mention them, not because I think it 

 at all probable they served as guides to the dogs in determining 

 the boundary line, but merely because they enabled us to observe 

 more accurately the phenomenon in question. 



This exhibition of canine intelligence was first observed by my 

 neighbors, who kindly pointed it out to me. It was repeated 

 almost daily for several months, and was a constant source of 

 amusement and wonder to those who witnessed it. The ques- 

 tion arises. How did the pointer know where the line ran, and 

 how did his canine neighbor know when he was safely across it? 

 The only answer which occurs to the writer is, that dogs (some 

 dogs, certainly) possess a very acute sense of boundary. 



Whether this sense is shared by other animals I am unable to 

 say, though, on this point, it is possible that some of your readers 

 may be able to throw light. The question is certainly an inter- 

 esting one from its bearing on the general question of animal 

 intelligence. F, Tuckebman. 



Berlin, Germany, Feb. 38. 



The Results of Search for Paleolithic Implements in the Ohio 

 Valley. 



Those engaged in the recent discussion of Glacial Man have 

 had little to say of the Ohio Valley. Without laying any claim 

 whatever to geologic skill, I will submit some extracts from my 

 private journal. These are submitted from the standpoint of a 

 "field searcher" who knows nearly all the village sites and 

 primitive remains of southern Ohio. 



"May, 1891. Found in ash-pits near the Little Miami River, 

 at Fort Ancient (Warren County), several objects of the character 

 of those in the United States National Museum labelled from 

 New Jersey and District of Columbia, commonly called paleo- 

 liths. These are in various styles — broken and whole, rude and 

 well formed, large and small. Pottery fragments, bones, and 

 flint chips side by side with the rough forms. 



" Spent a large part of three days in inspecting the river banks, 

 gravel strata and river bars. Pottery, several cells, arrow-heads, 

 and paleoliths numerous. Two hearths discovered, the one six 

 and the other nine feet below the surface. A modern brick was 

 found lying just above one of them. Rough implements were 

 gathered from the village sites and in the clay and sand of the 

 river banks. No implement was seen protruding from the gravel 

 layers. 



"Rowed up the stream all day Saturday. Three experienced 

 field-searchers were in the boat. No gravel bank was seen which 

 contained implements. We saw no spot in clay bank, on village 

 site or bar where only rude implements of paleolithic type (or 

 approaching that type) were found. The rude objects, tinished 

 objects, pottery, etc., are always found together. Careful 

 searching long continued might reveal isolated paleoliths. The 

 river frequently washes cans, bricks, etc. out of its banks and 

 transports them to remote parts. Just so it might carry a piece 

 of pottery or a paleolith to a gravel bar and deposit it. A finder 

 of an implement thus deposited would attach to it great import- 

 ance, especially so were he a stranger in the valley." 



This important point has been overlooked in the discussion. 

 So far as Ohio goes, I think I am safe in saying, Dr. Metz is the 

 only thorough archseologist who claims to have found paleoliths 

 in the drift. All others have been found by travellers or persons 

 not familiar with the prehistoric sites of occupation. Professor 

 Wright does not claim to have found them himself. How is it 

 that those of us who spend all of our time in arcbseologic work 

 cannot find them ? Were they so numerous in drift, surely we 

 could see them whether we knew anything about geology or not. 

 The type is fixed in everyone's mind, and while a searcher might 

 not be able to name the deposit in which the implement occurred, 

 he certainly could tell the implement when he saw it ! 



Dr. Cresson — strong in " paleolithic faith " — never found one 

 specimen while he was for four months in my camp in Paint 

 Valley, Ross County. Yet he often searched the creek banks or 

 gravel exposures. My men, all good specimen hunters, quick to 

 see an artificial object, could never find them in any kind of 

 stratified gravel. I lay no claim to a knowledge of the gravels, 

 but had implements been found in them geologists from Colum- 

 bus or Cincinnati would have examined and named the deposits 

 for me. During the coming summer I will spend as much time 

 as possible in a further search for implements like those found 

 by Metz and Mills. Any number can be found on the surface, 

 but as yet I have not been able to find one in gravel layers. 

 Probably my eyes are not sharp enough ! 



Warren K. Mooeehead. 



5,215 Washington Ave., Cliicago, 111., Mar. 24. 



Probable Causes of Rainy Period in Southern Peru. 



In ycur issue of Oct. 21, Professor A. E. Douglass of Arequipa 

 Observatory presents important facts evidencing a former rainy 

 period in that region which is now nearly rainless. This change 

 he attributes to a considerable increase in the elevation of the 

 Andes in recent geological times. A most serious objection to 

 this theory is, that in order to entirely cut off the precipitation 

 from the trade- winds, an average height of broad mountain range 

 not exceeding 6,000 to 8,000 feet would be necessary. Our ex- 

 perience in the Hawaiian Islands is that the trade-winds rarely 

 surmount 5,000 feet of mountain, and, if they do tliis. they still 

 more rarely carry much rain over that height, nearly all the 

 moisture being precipitated upon the windward slope. It seems 

 impossible to suppose that the Peruvian Andes were not more 

 than at least one-half their present height during any recent geo- 

 logical period. 



I would suggest that the glacial period was the cause of the 

 former moisture of the climate of Peru. During the reign of ice 

 in the southern hemisphere, it seems probable that the weather 

 of the temperate zone was transferred to the tropic — was pushed 

 towards the equator. Peru would at that time have eujoved the 

 westerly gales now prevalent in southern Chili and Patagonia, 

 together with the heavy rains accompanying those winds. 



In support of the very recent existence of such temperate zone 

 climates in the tropics, I will adduce a fact stated to me by Pro- 

 fessor A. B. Lyons of Oahu College, who recently found on the 

 now arid slopes of Diamond Head buried land shells, Achatinellce, 

 of a species now only found upon the cold and wet summit of 

 Kaala, 3,700 feet above the sea. This fact indicates that the 

 present dry and warm climate of southeastern Oahu has been a 

 change from one formerly cold and wet, such as would probably 

 have existed during the ice age. 



