For scientists, a maze has been a useful tool for examining the analytic capacity of animals - chiefly mice and rats.

Seven years ago, however, a simple experiment demonstrated that a plant can identify the shortest route to food in a maze, prompting researchers to conclude that, "This remarkable process of cellular (analysis) implies that cellular materials can show a primitive intelligence."

The plant was one of the lower fungi, a slime mould, which is a thin organism that spreads across cool, shady, moist places. There are 550 different species of this type of mould in a variety of colours, some of them spectacularly beautiful. The experiment, led by Toshiyuki Nakagaki at the Bio-Mimetic Control Research Centre in Nagoya, Japan, is reported in Nature, 2000, 407:470.

Initially, the slime occupied all the paths in the maze, but within eight hours, it had identified the shortest path to the food, and had withdrawn from all other paths. Thus, said the researchers, it had "maximize(d) its foraging efficiency, and therefore its chances of survival."

It shouldn't come as a surprise that there are reputable scientists making the controversial claim that plants have memories, that they can store and interpret data, that they can integrate information, that they can identify relationships between dissimilar entities, and that they can analyze and even predict - as, for instance, when the mayapple, a simple white flower that is a forest-floor perennial, makes choices about future branch and flower formation years in advance.

A wealth of scientific detail supporting these claims is available in Communication in Plants, published last year by Springer-Verlag in Germany. The book is a collection of scientific papers edited by professors in Germany and Italy. Since it sells for $234.50 in Canada, looking for it in a university library may be a better option than buying it.

It may be stretching language to say these characteristics demonstrate primitive intelligence. Nevertheless, they point toward a capacity to perform tasks typical of what we call intelligence.

There are critics of such claims, however. For instance professor Laurence Moran of the University of Toronto's biochemistry department took exception to last week's column in his blog, saying systems biology "can be a very useful approach to a problem," but, "turning it into a religion isn't going to help."

He complains about too much rhetoric and not enough "real data." His blog is here. Scroll down until you come to "Junk DNA in the Toronto Star."

At this point, it's worth listening to a warning from Peter Harries-Jones, retired professor of anthropology at York University.

Harries-Jones has an academic background in the history of science and a career focus on communication.

And he accepts that plants demonstrate awareness, which he sees as necessary in order for them to undertake active co-ordination and organization in ecosystems.

He says, "New evidence of plant communication shows it occurs between plants and other organisms such as fungi, micro-organisms, insects and other animals. It also occurs among members of the same plant species, and between different plant species."

He fears that global warming will disrupt these patterns of messaging.

In a paper delivered to a New Orleans conference in October, he quoted Gregory Bateson, a pioneer in communication among organisms in ecosystems, to make the case that the first step in ecosystem collapse could be a breakdown of communication, "as a result of too much fragmentation of complex interactions ... This means," he said, "we should pay the closest attention to any changes in the response of living organisms to each other."

Paying attention to such changes is something that should interest even non-believers such as Moran - especially since a breakdown in communication may be already happening with bees.

More in my next column.