Flexible silicone tube and sickle: what they have in common

1. Step 1. Flexible silicone tube — is part of — Catheter. A channel for the liquid.
2. Step 2. Catheter — is part of — IV drip. A catheter.
3. Step 3. IV drip — has part — Syringe. A needle.
4. Step 4. Syringe — has part — Needle. A hollow needle.
5. Step 5. Needle — evolved from — Stone tool. Bone needles with an eye are part of the Palaeolithic toolkit.
6. Step 6. Stone tool — evolved into — Sickle. The first sickles had flint inserts.

Open Evothings