INTRODUCTOEY LETTEE. 
designation of productions of a country which they never 
inhabited. I have often had ocular demonstration of 
mistakes of this nature. Some years ago, one of my 
friends received a small collection of Javan reptiles from 
a young planter of Surinam, who pretended to have col- 
lected them himself in the vicinity of Paramaribo. I was 
ready to demonstrate to the new possessor, that Javanese 
animals, such as the Gecko guttatus, the Elaps furcatus, 
the Galeotes furcatus, and others, could never at the 
same time inhabit countries so remote from each other ; 
no faith was attached to my demonstrations. We often 
have reptiles of the islands of Ceylon and Java addressed 
to us from the Gape of Good Hope. M. Klinkenbeeg^ of 
Utrecht possesses a beautiful variety of the Boa Cenchria, 
which the mariners brought to him as if caught in Java ; 
and this error led the late Boie to establish a new species 
of Boa, belonging to the Old World. One of my friends, 
accepting the offer of an emigrant to the United States 
to make collections of natural history, furnished him with 
the means of making the first consignment. This consign- 
ment arrived ; it contained a collection of the reptiles of 
the Cape of Good Hope. Among the reptiles brought by 
M. Blomhoee, and described by the late M. Boie as all 
natives of Japan, are found species evidently from Java or 
the adjacent islands, as has been long ago demonstrated 
by MM. SiEBOLD and Bueger. The late M. Spix has 
figured among the animals discovered in Brazil, several 
species collected during his sojourn at Gibraltar, and he 
has even added notes on their manners, and on the places 
which they inhabit, &c. I shall say nothing of the work 
of Seba, in which most of the indications of the country 
are inaccurate. 
Other difficulties, not less considerable, present them- 
selves, in criticising monographic works. It would seem 
that their authors have not been always impressed with 
the aim which a figure should fulfil. According to my 
views, it should not simply serve to make the animal it 
represents recognisable, but it should be a substitute for 
the animal to him who cannot procure it for himself. 
Now, to answer this end, it is necessary that the figure 
