Not quite dragons

Here Be Dragons", in fine monastic calligraphy, is said to appear on almost any unexplored and uncharted maritime areas of early maps. This forbidding caution did not seem to deter ancient mariners, though, for off into the dragons' dominions they ventured, in sailing ships hardly bigger, one might suppose, than the lifeboats on a modern cruise liner. Even Darwin's Beagle was only 235 tons, and young Darwin, a big man, had to share a cabin with two others, sleeping in a hammock within inches of the skylight above him. He did not record encounters with dragons, but those who went before him were undoubtedly shaken by experiences of sea creatures which their imaginations could easily equate with what they had heard of fire-breathing monsters.

The most interesting parts of Monsters of the Sea deal with the real ones, the giant squid on which sperm whales appear to feed, manta rays, often called the devil fish, which I myself saw three of from a crow's-nest lookout in World War Two, easily approaching the beam of my own vessel which was more than 50 feet. It is known that these gentle, plankton-feeding mantas do sometimes, for purposes unknown, leap from the water and crash down on deck dramatically, as some whales like the humpback are fond of doing; and for those witnessing so terrifying a spectacle for the first time, with many months of fevered remembrance in which to embellish their experiences before getting home again, it was little wonder they spoke and wrote of the monsters so well described here by Richard Ellis.

Ellis is excellent, too, on the mysteries of the sperm whales. It is really quite shameful that while we can cross space to the moon and back, while the Hubble space telescope appears to be eyeing the very fringes of the expanding universe - if there are any fringes - we know so little about many of the creatures with which we share this planet; and out of them all Ellis has convinced this writer that the sperm whale is by far the most intriguing.

The well-known mystery of how this - and some other animals - can rapidly descend to great depths and return to the surface again without experiencing the agonising and often fatal "bends" or nitrogen narcosis human divers would suffer, is but one of far stranger habits of this great cetacean that Ellis details with compassion and interest. What is the purpose, for instance, of that great mandible with its peg-like teeth that do not appear to be used for biting anything, let alone giant squid?

Much of Monsters of the Sea, however, is given up to material seen repeatedly in various other publications over the years. A whole chapter on the Loch Ness monster, for instance, makes hackneyed reading, and the illustrations from etchings of giant octopuses dragging whole ships and their crews down to terrifying destruction have appeared so many times before in print that large parts of this volume leave one with a powerful sense of deja vu.

No one will deny that there may be gigantic life forms in the great depths and expanses of the planet's extensive oceans we have not yet discovered, but individual monsters, such as notorious Nessie, or even a few monsters, will not do - there have to be many hundreds of a single species to form a viable genetic pool, and that being so, surely by now we would have had more evidence than a few blobs of protoplasm, a strange shark-like Megamouth, or a plethora of imaginative Victorian engravings, let alone a lengthy though scholarly book like Monsters of the Sea, as convincing evidence?

Harry Miller, a fellow of the Zoological Society, lives in Madras.