Oliver has recently used the second level approach with the largest snakes, and has come to these conclusions: the anaconda reaches a length of at least 37 feet, the reticulate python 33, the African rock python 25, the amethystine python at least 22, the Indian python 20, and the boa constrictor 18 -- 1 2.

Bernard Heuvelmans also treats of the largest snakes, but on the third level, and is chiefly concerned with the anaconda. He reasons that as anacondas 30 feet long are often found, some might be 38, and occasional ``monstrous freaks'' over 50. He rejects dimensions of 70 feet and more. His thirteenth chapter includes many exciting accounts of huge serpents with prodigious strength, but these seem to be given to complete his picture, not to be believed.

Detailed information on record lengths of the giants is given in the section that follows.

Discussions of the giants one by one will include, as far as possible, data on these aspects of growth: size at which life is started and at which sexual maturity is reached; time required to reach maturity; rate of growth both before and after this crucial stage; and maximum length, with confirmation or amplification of Oliver's figures. Definite information on the growth of senile individuals is lacking.

At birth, this species varies considerably in size. A brood of twenty-eight born at Brookfield Zoo, near Chicago, ranged in length from 22 to 33 -- 1 2 inches and averaged 29 inches. Lawrence E. Griffin gives measurements of nineteen young anacondas, presumably members of a brood, from ``South America''; the extreme measurements of these fall between the lower limit of the Brookfield brood and its average. Raymond L. Ditmars had two broods that averaged 27 inches. R. R. Mole and F. W. Urich give approximately 20 inches as the average length of a brood of thirty from the region of the Orinoco estuaries. William Beebe reports 26 inches and 2.4 ounces (this snake must have been emaciated) for the length and the weight of a young anaconda from British Guiana. In contrast, Ditmars recorded the average length of seventy-two young of a 19 -- foot female as 38 inches, and four young were born in London at a length of 35 or 36 inches and a weight of from 14 to 16 ounces. Beebe had a 3 -- foot anaconda that weighed only 9.8 ounces. A difference between subspecies might explain the great range in size.