Great Snakes 3209 
as the phenomenon is called, occurs in the case of certain side-necked tortoises. And 
it is one of the puzzles of science to determine whether these peculiarities should be 
explained by a migration down different continents from the north, or by means of 
a direct equatorial land connection. 
The true Boa constrictor, as already mentioned, is a comparatively small species, 
probably not much exceeding a dozen feet in length. On the other hand the giboa, 
or anaconda (Hwnectes mwrinus), which differs from the true boas by the number and 
arrangement of the horny shields on the head, appears to be the largest of all living 
snakes, although we are yet in the dark as to its maximum dimensions. It is commonly 
reported to attain a length of thirty-three feet; but it has been well remarked that 
while there is no inherent improbability in such statements, the giant specimens seem 
to have a knack of keeping out of the way of the naturalist. 
Thirty-three feet is, however, scarcely within measurable distance of the dimensions 
which have been tentatively assigned to the anaconda. Charles Waterton, for instance, 
mentions that when in Angostura he was shown part of a serpent’s skin which, judging 
from its amazing thickness, he attributed to an individual which could not have 
been less than seventy feet. And Waterton was not given, knowingly, to romance! 
Possibly the real explanation may be that this abnormally thick skin belonged to an 
anaconda of unusual girth. And that such exist is testified by the following statement 
made by Mr. Paul Fountain in “ Mountains and Forests of South America.” This 
writer observes: “I shot an enormous boa, which, though only seventeen feet long, 
was fifty-two inches in girth in the thickest part, and this great size was not owing 
to the reptile having recently fed, for the stomach was empty.” 
Although we are not prepared to accept anacondas of seventy feet in length, it 
seems quite probable that specimens largely exceeding, either in length or girth, any 
yet known to science may occasionally be met with. To such overgrown monsters 
the Spanish inhabitants of South America, according to Waterton, apply the name 
Matatoro, or bull-killer. 
This opens up the question as to the maximum size of the animals boas and 
pythons are able to kill and devour. On this point I may quote from Dr. Gadow, 
who, in the Cambridge Natural History, writes as follows:—“It is obvious that a 
large snake, twenty feet long, half a foot thick, and weighing several hundred pounds, 
can crush a tiger, a stag, or even a cow; but common sense tells us where to draw 
the line when it ‘comes to the swallowing of the prey. Small game, although of 
Photo by A. S. Rudland. ANACONDA: 
