Final installment in the series, and my 666th post.

Kitten walking through a maze during psychological testing at Brooklyn College. Nina Leen, 1941. Source: LIFE Photo Archive, hosted by Google.

life:

The November 17, 1958 issue of LIFE found naval researchers testing the effects of being upside-down for prolonged periods of time on animals in an attempt to learn about the disorientation astronauts would likely experience on space flights.

The research included using magnets to affix animals to the ceiling. Unsurprisingly, one key finding of the study was that the adorable kitten was “extremely fatigued” by the experience of walking upside-down.

Here, in celebration of LIFE’s 75th anniversary, LIFE.com presents the most wonderful and, in some cases, the most thoroughly bizarre science and technology photos ever to appear in the magazine.

Nina Leen, Cat being used by scientists conducting psychology testing at Brooklyn College, 1941. Source: LIFE Photo Archive, hosted by Google.

Nina Leen, Scientists conducting psychology testing on cats at Brooklyn College, 1941. Source: LIFE Photo Archive, hosted by Google.

Nina Leen, Kitten walking through a maze during psychological testing at Brooklyn College, 1941. Source: LIFE Photo Archive, hosted by Google.

Nina Leen, Scientists conducting psychology testing on cats at Brooklyn College, 1941. Source: LIFE Photo Archive, hosted by Google.

Nina Leen, 1941: “Kitten making its way through a maze during psychology testing at Brooklyn College.” Source: LIFE Photo Archive, hosted by Google.

Like this little guy? Me too. There’s more here.

Nina Leen, [Cat being used by scientists conducting psychology testing at Brooklyn College], 1941. Source: LIFE Photo Archive, hosted by Google.

Buggy kitten eyes!

Nina Leen, [Kitten walking through a maze during psychological testing at Brooklyn College], 1941. Source: LIFE Photo Archive, hosted by Google.

Nina Leen, [Cats running into a room under observation of scientists conducting psychology testing at Brooklyn College], 1941. Source: LIFE Photo Archive, hosted by Google.