Nefesh HaChayim, Reb Itzele's Long Annotation

And every variation in the nature of everything in the world, from the depths of the earth to the skies above, everything is the effect of the variation in how the four elements combine, for they are the primeval roots, and their combination are the inner aspect of each thing. And based on the quality of their combination inside them are drawn the many different details in each thing: in the physical appearance and their color among the inanimate443Heb.: ba-doe-m’mim, and the variation among the vegetation444Heb.: ha-tz’ma-khim in their flavor, appearance and color. And so too among the natures of all animals445Heb.: ba-ah-lei chayyim, the appearance of their limbs/ organs, their appearance and shape and behavior change according to the combination of their soul-Neffesh and their blood from the four “humors”446The “humors” are the four liquids found in various balances in the human body: black bile, yellow bile, green phlegm and red blood, corresponding to earth, fire, water and air., they being the four elements.