41.   Burning all the tropical forests in the world would decrease the proportion of oxygen by four-hundredths of one percent.

42.   Bush has expressed general concern for these issues, and on Friday singled out the preservation of tropical forests as a priority in his diplomacy with Latin America.

43.   Congressional legislation covering civilian agencies like the Agency for International Development makes the protection of tropical forests and biodiversity a priority in dispensing foreign aid.

44.   Dense tropical forests climb staircases of misty hills.

45.   Destruction of tropical forests has often been cited as a threat to neotropical migrants.

46.   Dr. William A. Schutt Jr. went looking in the tropical forests of Trinidad to prove that not all vampire bats are equal.

47.   Environmental protection is still a relatively new concept in Thailand, whose waters and once-vast tropical forests have been ravaged by pell-mell development.

48.   Feral pigs, imported from Europe long ago for food, roam the tropical forests, digging up roots and clearing the way for foreign plants.

49.   He added that only a handful of companies are actually screening the tropical forest for potential medicines.

50.   Heliconius butterflies live in the tropical forests of Central and South America aside from one species, Heliconius zebra, which has taken a liking to Florida.