THERE were a few things in the forest that I would have preferred not to encounter, however.

The first time I had to pull an inflated squishy black leech off my leg, I have to admit I felt slightly sick to my stomach. Somehow, it had attached itself at both ends, and I had a hard time getting it off.

The worst thing about leeches is not their bites--which do not hurt at all--but the anticoagulant they inject in your blood. Leech bites can bleed for hours after the buggers have been removed.

While out trapping rats in the rain for his research, Sean got two leeches stuck in his eye. It took our professor half-an-hour to pull them out with tweezers. And Sean walked around with the whites of his left eye blood-red for two weeks.

But leeches are nothing, I decided, compared to the horrors of the stinging tree. The plant has big enticingly soft leaves. But those fuzzy leaves are covered with fine spines that stick in your skin if you even think about walking near the plant.

The spines cause a painful itchy rash. But what's worse, they harbor a poison that attacks the lymph nodes, filling your body with a dull heavy and persistent pain for days. After the initial shock wears off, victims feels like they are carrying weights in their armpits or other extremities.

And I don't even want to talk about the ticks...

EXCEPT for brief, bi-weekly reprieves to the pubs of Cairns, one hour away, we spent all our times in the verdant forest. One of many tropical rainforest fragments scattered along the northeastern coast of Australia, this area has been extensively cleared for settlement, agriculture and logging. And the Australian wildlife has suffered dramatically, with many species are endangered. Others were probably lost before they were ever known.

Fortunately, a referendum in 1986 passed declaring much of the area from Townsville to Cooktown a "World Heritage" area and establishing a ban on logging in all those regions.

The site impressed me with its self-sufficiency. Solar energy and one small gasoline-powered generator--only periodically turned on-was enough to support the 30 of us.

IN Australia, a lot of things were different for me. For the first time in my college career, I actually attended every single lecture in every course for an entire semester. I did all of the assigned reading in all of my courses, and I completed all of the assigned work. I am not sure about too many students at Harvard, but I don't think that a majority of students could say the same thing for one course, let alone a whole semester.

But of course, my classes were a little different from the average Harvard lecture. One, independent research, consisted of donning a miner's headlight, boots and a notebook and traipsing off into the rainforest at night hunting for the ubiquitous cane toads.

There is no place darker than a rainforest at night. With my fingers touching my nose, I still could not see my hand, although there were fireflies and phosphorescent fungi to light the place up.

The toads, introduced to the continent 50 years ago in a failed attempt to control the sugar cane-eating beetle, were all over the paths around camp on rainy nights. The squat, green creatures have multiplied out of control, and they are often systematically killed by motorists and biologists.

Once I had caught the toads, I tied a string around their bellies and let them go. The string was attached to a spool, which I fastened in the ground with a nail. The toads hopped off and I returned in the mornings, following the track left by the string, to find their homes and record an average home range.

In case you want to know, the average home range for an adult cane toad is 340 square meters.

I said good-bye to the rainforest from the top of a ladder next to our camp. It had become my favorite perch, and I could look out at the forest and the sinking sun.

A flock of sulphur-crested cockatoos was circling above the trees, lit up with the yellow light of a late afternoon. I never heard them in the dawn chorus, but their cacaphony announced the moving cloud of wings a full five minutes before they appeared.

They disappeared behind the trees as I stepped into the van. But I could still hear the cockatoo screeching as we drove from the rainforest and down the mountain to civilization.