DECEMBER 31, 1897.] 
vised, but it could not have been freer of all 
traces of former occupation if it had been thor- 
oughly swept up the day before. Only once 
was it that a doubt crossed my mind, when 
I came across a cairnlike monument which 
looked as though it might have been con- 
structed by human hands. But the possibility 
of its being the result of erosion is also quite as 
strong as the other. No bits of pottery, no 
broken household utensils of any sort, no traces 
of construction of any sort were visible, not 
even the deepening of the natural surface of 
any of the rock cavities for the purpose of rain- 
water storage for drinking use, betrayed even 
the slightest indication that the top of the 
Mesa had ever been the prehistoric home of 
the Acomas.”’ 
In Harper’s Weekly (August 28) Professor 
Libbey makes the following statement : 
““There were no remnants of pottery, or frag- 
ments of household utensils, or implements of 
any kind; no water-tanks for the storage of 
rain water ; one object alone looked as though it 
might have been built by human hands, and 
that was a small cairnlike mass of stones.’’ 
In this article Professor Libbey pictures the 
operation of his gun, boatswain’s chair, etc.; 
but where is the ‘cairnlike mass of stones’ 
which he found, the origin of which he seems to 
be at such a loss to determine? Itseems to me 
that this doubtful feature is the most important 
of all the observations made by Professor Lib- 
bey during his brief stay on the summit, and 
yet he left it unphotographed. 
Later, in the Philadelphia Press (October 10), 
Professor Libbey says : 
“The cairn-like pile of rocks, which I am 
glad Mr. Hodge so clearly decides is a cairn, is 
possibly the best proof of a mere visit, for even 
primitive people are not given to building cairns 
in their back yards. * * * * 
“‘T am inclined from the facts which I was 
able to observe upon the top of the Mesa still (/) 
to believe that while the top may have been 
visited, no evidence exists at present of its ever 
having been permanently inhabited. 
“T picked up some fragments which re- 
sembled ancient pottery, but could not persuade 
myself that they were. I took them to Mr. 
Pearce [one of the reporters who accompanied 
SCIENCE. 
995 
Professor Libbey], and he agreed with me that 
they were not pottery.”’ 
The fact that the Professor fails to speak of 
having occupied part of his precious two hours 
in the erection of the lichen-covered rock-pile 
which we found and photographed, and the fact 
also that the structure occurs on a spot so pro- 
tected from the surface wash that it may have 
stood there for ages, were sufficient to mislead 
anyone, and my error may be regarded as ac- 
knowledged when Professor Libbey states 
openly that the monument was erected by 
himself. 
The better part of two days of research by 
the members of my party, each of whom had 
his eyes open, failed to reveal any other arti- 
ficial monument than the one which I have 
figured. Iam, therefore, safe in concluding that 
there is no ground whatever for the belief that 
any other artificial cairn or cairn-like structure 
exists on the summit of the Enchanted Mesa. 
If Professor Libbey constructed the cairn re- 
ferred to, then he might have spent the portion 
of the two hours consumed by its erection in a 
way more profitable to archeplogy. Whether 
or not it was erected by him, the evidence of 
the former occupancy of the summit of the En- 
chanted Mesa is not weakened in the slightest 
degree. 
F. W. Hopee. 
BUREAU OF AMERICAN ETHNOLOGY, 
WASHINGTON, December 14, 1897. 
LAMARCK AND THE ‘PERFECTING TENDENCY.’ 
In preparing some lectures on the history of 
evolution theories I have come across a curious 
difference of opinion among distinguished writ- 
ers. Professor Osborn (‘From the Greeks to 
Darwin,’ p. 163) seems to contradict himself in 
the same paragraph. He says: ‘‘ Lamarck be- 
lieves that we see in nature a certain natural 
order imposed by its Author, which is mani- 
fested in the successive development of life; 
we thus study natural forces and nature aban- 
doned to its laws. In this sense we see nature 
creating and developing without cessation to- 
wards higher and higher types. External con- 
ditions do not alter this order of development, 
but give it infinite variety by directing the scale 
of being into an infinite number of branches.’’ 
