The cause of nutrition and growth resides not in the organism as a whole but in the separate elementary parts—the cells.

~ Theodor Schwann

Theodor Schwann Biology Cell Theory Cells Microbiology Nutrition Science

The principal result of my investigation is that a uniform developmental principle controls the individual elementary units of all organisms, analogous to the finding that crystals are formed by the same laws in spite of the diversity of their forms.

~ Theodor Schwann

Theodor Schwann Biology Cells Diversity Investigation Organisms Result Science