320 Tropical Zoology. (July, 
many much larger masses—must have fallen during that 
period. Thus, not only without straining probabilities, but 
by taking only the most probable assumptions as to the 
past, we have arrived at a result which compels us to 
believe that the moon’s surface has been very much marked 
by meteoric downfall, while it renders it by no means un- 
likely that a large proportion of the markings so left would 
be discernible under telescopic scrutiny; so that strong 
evidence exists in favour of that hypothesis which one or 
two writers (who presumably have not given great attention 
to the recent progress of meteoric astronomy) would dismiss 
‘without consideration ” (the way, doubtless, in which they 
have dismissed it). 
I would, in conclusion, invite those who have the requisite 
leisure to a careful study of the distribution of various orders 
of lunar marking. It would be well if the moon’s surface 
were isographically charted, and the distribution of the seas, 
mountain-ranges, and craters of different dimensions and 
character, of rills, radiating streaks, bright and dark regions, 
and so on, carefully compared inter se, with the object of 
determining whether the different parts of the moon’s sur- 
face were probably brought to their present condition during 
earlier or later periods, and of interpreting also the signifi- 
cance of the moon’s characteristic peculiarities. In this 
department of Astronomy, as in some others, the effective- 
ness of well-devised processes of charting has been hitherto 
overlooked. 
i 
IV. MODERN RESEARCHES IN TROPICAL 
ZOOLOGY.* 
feed modern books of travel are justly ranked 
among the dreariest of literary productions. ‘Their 
authors treat the countries which they visit merely 
as a stage for the display of their own imagined perfections, 
their omniscience, their courage, their skill as sportsmen, 
and above all, the importance of their mission to the dis- 
tinguished personages with whom they became acquainted. 
To all this the work before us offers a complete and a 
delightful contrast. Mr. Belt does not obtrude his own 
personality upon us. Like all genuine men, he forgets 
‘‘self” over his subject. Instead of informing us whether 
rw” 
*The Naturalist in Nicaragua; a Narrative of a Residence at the Gold Mines 
of Chontales, By Tuomas BELT, F.G.S. London: John Murray. 
