Let us speculate a little on the maximum size of the anaconda. If, in a certain part of the range, it starts life 1 foot longer than do any of the other (relatively large) giants, and reaches maturity at, let us guess, 18 inches longer than the others, a quadrupling of the maturity length would result in a maximum of (nearly) 40 feet.

When it comes to rate of early growth, the Indian python leads with a figure of about 3 feet 6 inches per year for the first two years, more or less. The African rock python, a close second, is followed in turn by the reticulate python. There are few data on the boa constrictor, those for the anaconda are unconvincing, and there is nothing at all on the amethystine python. It seems likely that the Indian python comes out ahead because records of its growth have been made more carefully and frequently; it responds exceptionally well to captivity and does not reach proportions that make it hard to keep.

I cannot make sense out of the figures for post maturity growth; at best the annual increase appears to be a matter of inches rather than feet. Until better records have been kept over longer periods of time and much more is known about the maximum dimensions, it will be wise to refrain from drawing conclusions.

It is often stated that the largest snakes require five years to attain maturity, but this apparently is an overestimation. The best way to determine the correct figure (in captives) is by direct observation of pairs isolated from birth, a method that produced surprising results: maturing of a male Indian python in less than two years, his mate in less than three; data on the boa constrictor about match this.