REVIEWS. 181 
‘Of the carved chalchihuitls, like those d ibed from FiG. 48 to Fia. 62, 
I have seen but three specimens outside of my own collection: one al- 
ready alluded to in the Christy Museum of London, another in the late 
Uhde Museum near Heidelberg, and a third in the Waldeck collection in 
Paris. 
The question how these obdurate stones were engraved, drilled, and 
sawn apart, or from the blocks of which they once formed a portion, is 
one likely to arise in most minds. It is one that has puzzled many in- 
quirers; nor do I pretend to give an answer, except that the drilling was 
pur performed by a vibratory drill, composed of a thin shaft of cane 
b o, the silica of which was reénforced by very fine sand, or the 
I of us very article — treatment. The strie shown in the orifices 
are proof of something of the kind, and the esteem attached to these 
As regards the sawing, of which the backs of Fias. 51, 52, and 64, afford 
striking examples, we may find a clue in the accounts of the early chron- 
iclers, who relate that they saw, in Santo Domin ngo and elsewhere, the 
ines use a thread of the cabuya ai agave), with a little sand, not only 
in cutting stone, but iron itself. The thread was held in both hands, and 
drawn right and left sis worn out s attrition, aim then changed for a 
new one, fine sand and water being constantly supplied. 
Not a few inquirers Vise the hypothesis pe most of the raised 
and sunken figures on various stones in Mexico, Central America, and the 
mounds of the United States. were produced by persistent rubbing or 
abrasion — a general hypothesis which I shall not dispute. B bjeets 
m the mounds, as well as from other points on the continent, we have 
distinct Meg f the use of graving or incisive tools of some kind — 
as for instance in ad heretyk in Fic. 54, which are cut in a stone so ° 
hard that the blade of a knife produces scarcely any impression on its 
polished surface. 
E RECORD OF ZOOLOGICAL LITERATURE FOR 1868.* — We have before 
out the part on insects; or the conchologist without that on shells; or the 
ae ates be at all informed on the progress of his speciality unless 
work to refer to. Its preparation isa labor of love by the 
editors aa its liberal minded publisher, Mr. Van Voorst; and the work is 
a credit to their heads and hearts. 
*Vol. V. Edited by Dr. A. eet London, Van Voorst, 1869, 8vo, pp. 592. Price re- 
duced to $10a vol. The Record id 1868, also in parts: Part 1, Foin, $3.50; Part 
2, Entomology, $1.00; xe s pb aad agde and the Lower Animals, $3.50. For sale at the 
Naturalist's Book Agenc 
