Weird laboratory object

Someone at another school has found this and is trying to identify it - I've checked a 1927 biology catalogue and a 1952 chemistry catalogue with no success, but maybe someone here has an idea what it is. It's made of earthenware, and the wide part (at the bottom, but for all I know it's intended to be at the top) is 10.5cm wide. The top bit that looks like a handle is solid, not hollow, so it isn't a funnel.

My guess is something like a cover for a drain or some sort of jar, but does anyone know for sure?

Mad science at its finest!

Gacked from sjgames

Japanese scientists have genetically engineered silk worms with coral or jellyfish genes to produce silk that glows in UV light - in three different colours:

http://io9.com/transgenic-silkworks-spin-glowing-fluorescent-silk-541389233

So long as you don't end up with silkworms that sting you I suppose it's OK...