"Smell was our first sense. It is even possible that being able to smell was the stimulus that took a primitive fish and turned a small lump of olfactory tissue on its nerve cord into a brain. We think because we smelled."
Tissue
"Smell was our first sense. It is even possible that being able to smell was the stimulus that took a primitive fish and turned a small lump of olfactory tissue on its nerve cord into a brain. We think because we smelled."