
This fellow was found crawling across our porch this morning in the light just after dawn. It had rained heavily through the night. To give you actual perspective, he is about 3 1/2 inches in length. The snail does not get the respect he deserves and is called a slug when he is without his shell.
But once again, all one needs to do is look a little closer.
1. As the snail grows, so does its calcium bicarbonate shell. A snail will close off a section of its shell and add a new chamber as it grows, each chamber being larger than the previous one by a constant factor. As a result, the shells forms a logarithmic spiral, contributing to what is called the "golden ratio".
The proportion of the snail shell is an example of the "Golden Ratio" in nature.

Other names frequently used for or closely related to the golden ratio are golden section (Latin: sectio aurea), golden mean, golden number, and the Greek letter phi (φ). Other terms encountered include extreme and mean ratio, medial section, divine proportion (Italian: divine proportione), divine section (Latin: sectio divina), golden proportion, golden cut, and mean of Phidias.
The golden ratio has awed intellectuals of diverse interests for 2,400 years:
Some of the greatest mathematical minds of all ages, to present-day scientific figures such as Oxford physicist Roger Penrose, have spent endless hours over this simple ratio and its properties. The awe of the Golden Ratio is not confined just to mathematicians. Biologists, artists, musicians, historians, architects, psychologists, and even mystics have pondered and debated the basis of its ubiquity and appeal. In fact, it is probably fair to say that the Golden Ratio has inspired thinkers of all disciplines like no other number in the history of mathematics. From Phidias (490–430 BC) who made the Parthenon statues that embody the golden ratio, to Roger Penrose (b.1931) who found a symmetry that uses the golden ratio in the field of aperiodic tilings, which led to new discoveries about quasicrystals. The list of distinguished people who have used the phenomenal character of the shell of a snail to inspire new expressions in their particular fields are too numerous to list here.
Leonardo Da Vinci himself maintained that the human body has proportions that approximate the golden ratio. Some suggest that his Mona Lisa, for example, employs the golden ratio in its geometric equivalents.
In 1859, the Pyramidologist John Taylor (1781-1864) asserted that in the Great Pyramid of Giza built around 2600 BC, the golden ratio is represented by the ratio of the length of the face (the slope height), inclined at an angle to the ground, to half the length of the side of the square base, equivalent to the secant of the angle. The above two lengths were about 186.4 and 115.2 meters respectively. The ratio of these lengths is the golden ratio, accurate to more digits than either of the original measurements.
Credit cards are generally 3 3/8 by 2 1/8 inches in size, in the ratio 1.588, which is less than 2% from the golden ratio.
So, What is this that the snail carries on his back anyway??