With his restless wanderlust and insatiable curiosity, Dr. Harry could never stay put for long. He was always ready for another adventure, impatient to be on the move and see what was around the next bend. This was in spite of ill health—or perhaps because of it, as he intended to make the most of every moment. In 1931, Dr. Harry had suffered a heart attack and had given up his medical practice. He knew his health was beginning to fail, but he refused to let it stop him from doing what he loved—and that was to complete the building of the San Diego Zoo. He intended to travel to every continent in search of animals and plants for the Zoo, and even though his doctors warned him against heat, altitude, and physical strain, it just made him more determined to accomplish what he had set out to do.

In 1935, he and reptile curator Si Perkins jauntily embarked on a journey to the Philippines and Indonesia, bringing penguins, mountain lions, and sea lions to trade. As it turned out, and much to his disappointment, Dr. Harry did have to return home early because of his health, leaving Si to make the return arrangements for the large shipment of more than 400 animals they had acquired. But when that shipment arrived, it was spectacular, including binturongs, babirusas, orangutans, Celebes Islands macaques, Philippines turtles, and four species of gibbons, which gave the San Diego Zoo one of the most outstanding ape collections in the world.