Science: Rabbit Windows

In 1912 Anatomist Eleanor Linton Clark of the University of Pennsylvania accidentally ran a glass tube, fine as a hair, into her finger. A few days later, when her finger swelled, her husband & colleague, Anatomist Eliot Round Clark, probed out the sliver of glass. To their amazement, the Clarks saw tiny blood vessels sprouting inside the tube. Because they were scientists, that gave them an idea. They got three rabbits, slit the delicate skin of their ears over a dime-sized area, sandwiched the ears between oval glass windows, long as an egg. Then, because they were scientists, they proceeded to annoy the exposed blood vessels in various ways —to provide scientists with a view of dynamic living tissues in a living body.

With their ear-windows the Clarks were first to demonstrate (in 1930) that bruised lymphatic glands have regenerative power (the recuperating glands crawled right over the edge of the glass); that arteries and veins are bridged by blood vessels larger than capillaries. Other scientists, borrowing the now classic ear-window technique, have watched the effects of hormones, alcohol, serum and vaccine on the rabbits’ bloodstreams.

Last week at the annual Pittsburgh meeting of the Air Hygiene Foundation, the beaming Clarks exhibited two of their brood of 85 windowed rabbits. In one rabbit’s ear were tiny black specks of silica dust, which had been dropped into the raw tissue last June. Purpose of the experiment is to discover whether irritation of silica grains alone produces silicosis (dread “stony” lung disease often acquired by miners of silica) or whether complicating factors, such as mild tuberculosis, are necessary to bring on the disease.

Such ear-slitting, said Eliot and Eleanor Clark last week, is no more painful than piercing for old-fashioned earrings. The rabbits are placid and happy, wear warm grey flannel pajamas, take vacations in Europe, occasionally feast on ice cream and cake.