I have little information on the anaconda's rate of growth. Hans Schweizer had one that increased from 19 -- 1 2 inches to 5 feet 3 inches in five years, and J. J. Quelch records a growth of from less than 4 feet to nearly 10 in about six years. It is very unlikely that either of these anacondas was growing at a normal rate.

In 1948, Afranio do Amaral, the noted Brazilian herpetologist, wrote a technical paper on the giant snakes. He concluded that the anaconda's maximum length is 12 or 13 (perhaps 14) meters, which would approximate from 39 to 42 feet (14 meters is slightly less that 46 feet). Thus, his estimate lies between Oliver's suggestion of at least 37 feet and the 50 -- foot ``monstrous freaks'' intimated by Heuvelmans.

The most convincing recent measurement of an anaconda was made in eastern Colombia by Roberto Lamon, a petroleum geologist of the Richmond Oil Company, and reported in 1944 by Emmett R. Dunn. However, as a field measurement, it is open to question. Oliver's 37 -- 1 2 feet is partly based on this report and can be accepted as probable. However, many herpetologists remain skeptical and would prefer a tentative maximum of about 30 feet.

It is possible that especially large anacondas will prove to belong to subspecies limited to a small area. In snakes difference in size is a common characteristic of subspecies.

A Colombian female's brood of sixteen boa constrictors born in the Staten Island Zoo averaged 20 inches. This birth length seems to be typical. When some thirteen records of newly and recently born individuals are collated, little or no correlation between length and distribution can be detected. The range is from 14 to 25 inches; the former figure is based on a somewhat unusual birth of four by a Central American female (see chapter on Laying, Brooding, Hatching, and Birth), the latter on a ``normal'' newly born individual. However, as so many of the records are not certainly based on newborn snakes, these data must be taken tentatively; final conclusions will have to await the measurements of broods from definite localities.