The content you've requested is available without charge only to active Sigma Xi members and American Scientist subscribers.
If you are an active member or an individual subscriber, please log in now in order to access this article.
If you are not a member or individual subscriber, you can:
The queen conch is a marine snail that grazes seagrass beds in shallow Caribbean waters. It does so openly, and with little fear of natural predators: Unmolested by human fishers, an adult conch may live 20 years. This prodigious lifespan for an invertebrate is possible because of the conch's amazing shell, a defensive adaptation that represents the pinnacle of molluskan evolution. In conch shell, slender crystallites of calcium carbonate are bound by a proteinaceous glue into planks, sheets, and layers, and at each level of organization, adjacent elements are oriented at right angles. This architecture dissipates the force that might otherwise fracture the shell through a system of noncatastrophic microcracks. Breaking into a conch shell requires a crack to travel a tortuous path of false starts and switchbacks as it wends from sheet to sheet and layer to layer. In addition to such estimable toughness, the shell microstructure self-assembles and is self-healing, providing a lofty target that human engineers are beginning to match.
Connect With Us:
An early peek at each new issue, with descriptions of feature articles, columns, and more. Every other issue contains links to everything in the latest issue's table of contents.News of book reviews published in American Scientist and around the web, as well as other noteworthy happenings in the world of science books.
To sign up for automatic emails of the American Scientist Update and Scientists' Nightstand issues, create an online profile, then sign up in the My AmSci area.
JSTOR, the online academic archive, contains complete back issues of American Scientist from 1913 (known then as the Sigma Xi Quarterly) through 2005.
The table of contents for each issue is freely available to all users; those with institutional access can read each complete issue.
View the full collection here.
Receive notification when new content is posted from the entire website, or choose from the customized feeds available.