588 
ments of their own countries with those of 
Scandinavia, and a recognition of the simi- 
larity between them, the students from 
other countries of Western Europe were 
enabled to correlate and identify the culture 
of ‘the prehistoric man; and this knowl- 
edge finally crystallized into the universal 
recognition of the three prehistoric ages of 
stone, bronze and iron. The prehistoric 
man had but few kinds of implements: 
the hammer or maul, the hatchet, the 
knife, scraper, arrowpoint and spearhead, 
spindlewhorl, points of bone and horn, 
objects principally ornaments, of shell 
and pottery. These implements were sub- 
stantially the same in every locality so 
far as concerned the Neolithic period. The 
polished stone hatchets were identical 
whether found in the dolmens of France 
and England, the dolmens and shell heaps 
of Scandinavia, the lake dwellings of 
Switzerland, or the terramare of Italy; and 
in after years, as our knowledge of the pre- 
historic world increased, this similarity was 
found to extend throughout the Eastern 
and Western Hemispheres, as well as the 
islands of the sea. The similarity was not 
confined to one class of implements, but in- 
cluded nearly all in every age. To be sure, 
there were minor differences, but the imple- 
ments could be recognized as the same 
whenever found. For example, the hatchets 
were long or short, had a head or poll, well 
finished or left rude, and were round, flat 
or square in section. Those square in sec- 
tion were from Scandinavia ; short stumpy 
ones with unfinished poll, from the British 
Islands; the poll pointed or rounded and 
well finished, from Continental Europe; the 
button-headed, from Brittany. But with 
all this, they were always the same imple- 
ment. The material might differ with the 
locality, but otherwise, as to use and method 
of manufacture, they appeared the same. 
As investigation proceeded, this similarity 
of implement extended. The polished stone 
SCIENCE. 
[N. S. Von. XK. No. 252. 
hatchet of America was found to be the 
same, with the same differences of detail ; 
some from Illinois, made of flint, have a 
spreading edge, almost of a crescent form, 
the corners forming the points after the 
style of some of the battle-axes of medieval 
knights; those from Chiriqui are flattened 
on both sides by a sort of chamfer which 
makes them appear hexagonal in section. 
It has been argued that this similarity of 
implement was due to the similarity of 
human thought adapted to human neces- 
sity. The similarity of human thought 
and action under the same necessities may 
be admitted, although it necessarily had its 
limitations. 
The similarity of the implements found 
among different peoples widely separated, 
is not accounted for by the theory of human 
thought and human needs. ‘The classifica- 
tion of prehistoric culture into ages of stone, 
bronze and iron was based on the similarity 
of the implements in each age found in the 
respective countries, and this was the result 
of migration, communication or contact be- 
tween the peoples. 
Discoveries of Darwin and Boucher de Perthes. 
By the middle of the century students 
of prehistoric matters of the Old World 
had about accepted the prehistoric ages of 
stone, bronze and iron. Some attempts 
were made to discover the man who had 
made and used these implements; and the 
few skulls that had been gathered in earlier 
times, the significance of which had not 
then been understood, were subjected to re- 
examination in view of the new light upon 
prehistoric matters. Chief among these 
were the Canstadt skull, discovered in 1706, 
and the Engis skull, in 1822. In these 
studies the pathway of prehistoric science 
and knowledge was being slowly blazed 
when, in the year 1859, two great discov- 
eries relating to the origin and antiquity of 
man were published which had something 
