506 RETROSPECT. (CHAP. Xx1 
improving to a young naturalist, than a journey in distant coun- 
tries. It both sharpens, and partly allays that want and craving, 
which, as Sir J. Herschel remarks, a man experiences although 
every corporeal sense be fully satisfied. The excitement from 
the novelty of objects, and the chance of success, stimulate him 
to increased activity. Moreover, as a number of isolated facts 
soon become uninteresting, the habit of comparison leads to ge- 
neralization. On the other hand, as the traveller stays but a 
short time in each place, his descriptions must generally consist 
of mere sketches, instead of detailed observations. Hence arises, 
as I have found to my cost, a constant tendency to fill up the 
wide gaps of knowledge, by inaccurate and superficial hypo- 
theses. 
But I have too deeply enjoyed the voyage, not to recommend 
any naturalist, although he must not expect to be so fortunate 
in his companions as I have been, to take all chances, and to 
start, on travels by land if possible, if otherwise ona long voyage. 
He may feel assured, he will meet with no difficulties or dan- 
gers, excepting in rare cases, nearly so bad as he beforehand 
anticipates. In a moral point of view, the effect ought to be, 
to teach him good-humoured patience, freedom from selfishness, 
the habit of acting for himself, and of making the best of every 
occurrence. In short, he ought to partake of the characteristic 
qualities of most sailors. Travelling ought also to teach him 
distrust ; but at the same time he will discover, how many truly 
kind-hearted people there are, with whom he never before had, 
or ever again will have any further communication, who yet are 
ready to offer him the most disinterested assistance. . 
Norr.—The snake, described at page 96, with the curious habit of vibrat- 
ing its tail, is a new species of Trigonocephalus, which M. Bibron proposes 
tu call T. crepitans. 
