The photo below was sent to me by Gavin Thomas, a microbiology scientist at Palmerston North in New Zealand.
Gavin (and me) would like to know the most likely cause of the “spots” on the plate. It was just the one plate that they appeared on.
Any hypotheses on the cause are most welcome, just add them to the comments section, regardless of how outlandish or ridiculous they might seem!
Equally, let me know if anyone else has seen a similar phenomenen on their plates.
p.s. Any other interesting plate (or other) pictures are most welcome to be submitted to the website. Just email me on firstname.lastname@example.org