In 1839, Theodor Schwann would expand Schleiden's cell theory to include the animal world, establishing cell theory as the fundamental concept in biology. Schleiden included this article and others in a botany textbook--one that introduced new teaching methods which would dominate the instruction of botany for years.
Nasal septum: The dividing wall that runs down the middle of the nose, separating the two nasal ' cavities, each of which ends in a nostril. The nasal septum is composed of bone, cartilage, and 'membranes.
Noun [edit]. nasal â(plural nasals). 1  An elementary sound which is uttered through the nose, or through both the nose and the mouth simultaneously, such as m and n. ( 2 medicine, archaic) A medicine that operates through the nose; an errhine. ( 3 phonetics) A nasal vowel or consonant.