74 The American Geologist. February. iss'J 
"the study of the distribution of tiieso animals. My studies 
"of the stone and coral reefs and of the geology of Brazil 
"proved so very attractive to me that on the year following I 
"returned to Brazil, and spent ray vacation, several months, 
"in examining the coast between Pernambuco and Rio, ex- 
"ploring more particularly the vicinity of Bahia and tiie is- 
"lands and coral reefs of the Abrolhos. * * * 
"This volume was intended at first as a report to ))rofessor 
"Agassiz as the director of tl)e Thayer expedition, embracing 
"simply the results of my explorations as a geologist of that 
"expedition, together with those of my second independent 
"journey, both reports to be published among the contribu- 
"tions of the Thayer expedition. During the pi'eparation of 
"these reports, and in consequence of the delay in publication, 
"I have had the opportunity of examining more or less criti- 
"cally the works of the majority of the writers on Brazil, and 
"the volume, from a simple report of my own investigations, 
"has grown to a general work, in which I have incorporated 
"the best results of others who have written on the geolog\' 
"and phj^sical geograph}^ of lirazil." 
It is scarcely possible to review here with sufficient minute- 
ness a production of so great magnitude — so varied are the 
topics treated. The author's own studies were confined main- 
ly to the coast provinces, but, as above stated, he carefully 
compiled, in addition, the observations and conclusions of 
others, th^us giving the subject a wider scope than his own 
research would permit. Nor are matters of economic import- 
ance omitted; for instance, a chapter is devoted to gold min- 
ing, and the occurrence of the precious metal in many locali- 
ties is recorded. There are also notes on the occurrence of 
diamonds and. the diamond-washing industry. The last 
chapter (XIX) is devoted to a resume of the geology of the 
empire, and the volume concludes with an appendix of 30 
pages "On the Botocudos,'" one of the most primitive of the 
native races. Mention should also be made of the many illus- 
trations in the text and the large sketch map, compiled and 
drawn by the author himself and i-eproduced by the Osborne 
process. • 
Upon the establishment of the American Naturalist, in 
1867, Hartt became a contributor and from time to time, for 
