Suzie Q Explains Natural History
Paigetheoracle explains this photo:
Interesting gall, caused by wasp. Around my home town of Diss (Anglo-Saxon for ditch apparently and may refer to caves, said to be the entrance to the underworld, now buried under the Meer, a large body of water in the town – a lake by any other name), we found galls that were balls, created by a different species and also oak apples, bigger galls about an inch across and flattened, so they were half the width as they were high.
The only thing we know about gallwasps is that Dr Kinsey studied them extensively until he decided they weren't sexy enough and started in on humans.