An ecologist at the Abernethy Centre, Alastair manages within a few hours to link tall, flowering, purple-belled foxgloves - swaying in the sea breeze - to the role of the humble bumble bee and the existence of life on earth. The secrets of pollination, photosynthesis and the life cycle are unlocked beneath the shelter of a gnarled tree, embedded in the shoreline.
It is raining. Ten Primary 5 pupils from Carolside Primary in Clarkston, on the south side of Glasgow, sit on their rocky perch in splendid rapture and the H20 part of the complex compound story feels real enough. If this sounds like chemistry and biology, it is. And lots more besides.
The classroom is Arran, the Firth of Clyde island described by tourist industry scribes as "Scotland in miniature". Some 20 miles long by six wide, it boasts jagged, cloud-covered mountains, forest, acres of farm land, and a wonderful coastline. And midges, and a drop of H20.There are also some excellent centre teachers-cum-instructors at the Abernethy base. "Why do plants have very colourful flowers? Any ideas? Kevin?" Alastair quizzes the group as he looks out over Lamlash Bay. His excitement grows. "If you look behind, you will see a seal has popped its head out of the water". Sod's Law of Nature ruined the spectacle. By the time the class turns, the seal has dipped beneath the waters.
So it is back to the foxgloves. Alastair picks a foxglove and plucks a purple bell from its head. "So any ideas?" "To attract bees and other insects to them," Christopher answers. The mystery deepens. "Why do flowers want to attract bees, butterflies and wasps?" the tutor continues, the squawking oystercatchers overhead drowning his Attenborough approach.
The group gathers tightly round to inspect the bell and discovers minute hairs on the fringe of the petals. "Why do you think these are there?" Alastair goes on, seemingly up to his thousandth question that day. This is a trip in June but it sounds like official school work, only different. To keep out small insects," says someone under a hood. By now, it is clear the yellow and black honey-makers are in the picture. As luck would have it, only they seemed suited to squeeze inside the bell. "So what are they looking for?" the investigator probes. Someone says food, and it might even have been nectar. Nine-year-olds, perhaps, yet they seem to be getting the hang of the plot.
The tutor peels back the petals - one of the words he had written on the blackboard that morning - and exposes the pollen-laden stamen. Surely no self-respecting bee would fall for such a devious ploy of nature? It is getting tricky now, so, please, suspend your disbelief. Allegedly, Mr Bumble zooms in for a quick snack of energy-giving nectar, swirls about, gets decked in pollen for his troubles and buzzes off to the next bell for another feed. Amazingly, or so they would have us believe, microscopic pores from his wings drop off onto another stamen and transfer down to the seed which produces another foxglove. Alastair knows how to spin a yarn. He'll be telling us next the Vikings once ran the island and that its highest mountain at 2,866 feet is not called Goat Fell because a beast tripped but because Fell is the Viking word for a hill. Talk about a tall story.
The Countryside Explorer five-day course dovetails with the Scottish 5-14 environmental studies curriculum. The Abernethy Trust, which is a low-profile Christian-based organisation, has three other centres in Scotland.
Contact: The Abernethy Trust, Nethybridge, Inverness-shire PH25 3ED. Tel: 01479 821279. The Arran Centre is on 01770 860333. Countryside Explorer at Arran costs Pounds 85-Pounds 104+VAT per pupil according to the time of year