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. gouldi ; 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- 

 ture a ^ so a ddicted to water, the dusky hues are more 



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