A stilted story

　　踩高蹺的故事(陳繼龍 編譯)

　　Jun 29th 2006

　　From The Economist print edition

　　IF THERE were a Royal Society for the Prevention of Cruelty to Ants, Matthias Wittlinger of the University of Ulm, in Germany, would probably be top of its hate list. The reason is that Dr Wittlinger and his c________① have, as they report in this week's Science, been chopping the feet off ants. And not only that. They have been making other ants walk around on stilts.

　　假如有一個皇家防止殘害螞蟻協(xié)會的話，德國烏爾姆大學(xué)的馬提亞 威特林格可能會首當(dāng)其沖地成為其憎恨對象。這是因為威特林格博士和他的同事們在本周《科學(xué)》雜志上報道說他們砍去了一些螞蟻的腳。這還不算，他們還讓別的螞蟻踩著高蹺走路。

　　Saharan desert ants of the genus Cataglyphis have to travel long distances to discover food in their i________②, sandy environment. How they find their way home once they have done so is a mystery. Ants in more temperate climates often lay down chemical trails, but Cataglyphis, apparently, does not. Like honeybees and ancient mariners, they can n_______③ by the sun, so they know the general direction in which to travel. But, also like ancient mariners (who knew their latitude, but not their longitude), such solar reckoning cannot tell them when to stop.

　　撒哈拉沙漠的箭蟻不得不在貧瘠的沙質(zhì)環(huán)境中長途跋涉尋找食物。它們找完食物后如何返回蟻巢卻一直是個謎。溫和氣候環(huán)境下的螞蟻往往會在路途中留下化學(xué)記號，可箭蟻顯然不會。它們跟蜜蜂和古代海員一樣，可以通過日照導(dǎo)航，從而知道出行的大致方向。但是也跟古代海員一樣(他們只會辨認緯度不會辨認經(jīng)度)，這種根據(jù)太陽測算位置的方法無法告知它們該在何時結(jié)束行程。