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insult, and revenge. Instead of being a b^'on of peace and a 
comfort to men of quiet and studious habits, it would degenerate 
into a state of continual warfare, and few men of science would 
like to spend their lives on such a field of battle. 
To put an end to these remarks, I will only add that I think 
that when zoologists have long resided in a locality, and have 
made its productions the object of a particular study, such as 
liuppell, Bleeker, Bay, &c , their opinion is of greater value 
than that of a man, whatever may he his scientific acquirements, 
who remains in his study in Europe. A visit to a fish market, 
in bringing under your eyes thousands of specimens of a sort, 
will certainly lead you to a more correct idea of its variations 
than ean be obtained by the residing zoologist, who only has at 
his disposition one, or in all cases, a very few specimens, having 
lost their colours, and more or less their form, by dessication or 
preservation in spirits. . 
The study of Ichthyology has been with me, for many years, 
the object of a particular predilection. When in my youth, I 
spent nearly five years in the United States and Canada. 1 
collected a considerable number of fishes on the demand of 
Baron Cuvier. Later, when I was the Director of the Scientific 
Expedition sent by the King of the French, Louis Philippe, to 
South America, I devoted much attention to this subject, and the 
specimens collected on my return, by the Amazonas Eiver, are in 
the Parisian Museum ; but the greatest part of the vast collec- 
tion I had formed during the first three years overland, from Eio 
.Janeiro to Lima, was lost. A few of the dried specimens were 
saved, but all those put in spirits were destroyed, probably by 
the liquor becoming too weak, and also by the other incidents 
inherent to a two or three years’ trip on the backs of mules and 
horses. When the Eelation of this Expedition was published, after 
a few years’ delay caused by the political events which had agitated 
my country, I reserved for myself the Ichthyological part of the 
work. Having, after the Eevolution of 1848, been appointed 
French Consul at Bahia, I continued my researches in the 
northern parts of Brazil, and I was enabled to insert the results 
I obtained, by reason of the delay 1 have just explained, in 
the Eelation of my Expedition. Sent afterwards to the Cape 
of Good Hope, where I remained three years, during which 
