Holes on brick wall

Hi All,

I am looking at an apartment in the back streets of pyrmont and I found some very strange looking holes on the bricks wall, as these walls are in the sunroom they are technically indoor. I have attached a picture if anyone can identify these holes and let me know what these are and why they are there.

Thanks in advance.

 

I don't see any holes?
Do you mean the circular marks on the bricks? they look like a "feature" of the style of an older brick. They were often made that way. Are the circles kind of glossy/glassy? They used to sprinkle some glass which would melt in the kiln to make a feature on some bricks/

 

Thanks! I think that is what it is. The circles are filled with some glossy substance attached some more pictures.

 

They are silica inclusions in the clay of the brick which formed a glaze when fired in the kiln.