A few of the features that we usually find on certain things that we use are usually ignored and treated as vestigeal. The following are the things that have often been ignored by us inspite of being of great importance.
1. The blue side of the eraser- mystery unveils.
As children it was a mystery that everyone wanted to know about. The mystery has finally been revealed. The blue part of the eraser was used for heavy weights of paper while the pink part of the paper was used for light weight of papers that are prone to tearing apart.
2. Small disc under the lid of a plastic bottle.
It usually serves the purpose of keeping away the contents from moisture, prevents the material from disruption of the materials in the bottle, helps in sealing the bottle.
3. Caps having a small spike in them.
It serves the purpose to break the seal. This is usually the case with eye drop caps.