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nydus/On Growth and FormPublic
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Table of Contents

CHAPTER XI THE LOGARITHMIC SPIRAL

rates of growth are, apôÙproxôÙiôÙmateôÙly, as 3 to 1; while in spirals of constant angle from about 85ô¯ to 89ô¯, contact is attained when the rates of growth are in the ratio of from about 3ã€₤いã€₤5 to 9ã€₤いã€₤10.

A line diagram showing a logarithmic spiral, typical of a nautilus shell, with a line segment divided by points A, B, and C.

If on the other hand we have, for any given value of öÝ, a value of ö£ greater or less than the value given in the above table, then we have, respectively, the conditions of separation or of overlap which are exemplified in Fig. 278, a and c. And, just as we have constructed this table of values of ö£ for the particular case of simple contact between the whorls, so we could construct similar tables for various degrees of separation, or degrees of overlap.

For instance, a case which admits of simple solution is that in which the interspace between the whorls is everywhere a mean proportional between the breadths of the whorls themselves (Fig. 280).

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