AQUATIC LIZARDS 
Hydrosaurus, and some few other appellations, but which 
are all of the same genus ; this genus forms a family all 
to itself, occupying a very isolated position in the lizard 
series. To the casual eye, however, uninstructed in the 
technicalities of zoology, the monitor is a very average- 
looking lizard, distinguishable chiefly by its greater size, 
and by its rather long neck. But there is a good deal 
more in the monitor than meets the eye of the mere 
observer. Recourse must be had to the scalpel to em- 
phasize the divergences of the monitor from other lizards. 
It will be readily understood without a comprehensive 
knowledge of zoology, that it stands on a higher plane 
than most of its relatives by reason of the more compli- 
cated structure of the lungs ; for this added complexity 
means more efficient breathing and thus better aeration 
of the blood, and the effects may be felt in every part of 
the body. A long neck, too, is evidence of advance, for 
the lower creatures, frogs, fish, and most lizards, are 
quite apoplectic as to neck, and as a consequence their 
hearts are in their throats. The heart of Varanus is 
placed farther back, and it is thus more like the higher 
animals, such as birds and mammals. But these details 
are mentioned in order to illustrate the fact that it is 
rash in zoology to judge entirely by external appear- 
ance ; they show that two creatures much alike to out- 
ward view, may be profoundly different in reality. There 
are about thirty-four or -five different species of 
monitors, of which we figure here, V. gouldt ; the largest 
is not the lizard of the Nile, but a huger beast—even 
seven feet in length—which inhabits certain parts of 
tropical Asia, and whose name is Varanus salvator. 
Most of these creatures are of a ““ subfusc ” hue, but get 
brighter in certain places, an added yellowness being the 
chief alteration. There is certainly one form which is 
variegated by bright green. Being ground-living crea- 
tures, also addicted to water, the dusky hues are more 
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