Soma, the Pulmonary Arteriole

 It is now established beyond doubt that the soma plant refers to the the pulmonary arterioles that grows in the distal end of the respiratory acinus. Ample textual references pertaining to the soma ritual have sealed its identity and confirmed our earlier hunch. These passages mention how the soma plant is pressed by the stones at first and that its juice is then mixed or brought into close contact (upaparcana) with milk or water and even filtered (implying a sieve like mechanism) by means of sheep skin. All these details have left no room for any doubt in the mind of this author regarding the identity of this mysterious plant of the Vedas (and even other ancient cultures such as the Avestan).

It is the pulmonary arteriole at the acinar level that is referred to as the "soma plant" in the Vedic texts. This "plant" is crushed into capillaries under the "rocks" of the alveoli. Then, the "milk", the vivifying stream of oxygen molecules, is added to its "juice", the deoxygenated blood, flowing through the capillaries. At the same time, "sheep skin (wool?)", the membrane of the alveoli, is used as a highly effective filter to filter out the carbon dioxide inherent in the pulmonary flow. The net result of all these "activities" is that the blood, hitherto deoxygenated, becomes reoxygenated and exceedingly pure. It is this purified soma juice that brings delight to the microcosmic world as the ambrosia for the neural entities.  

The pulmonary artery is crushed as it were by the stones of the alveoli into capillaries. These capillaries are apposed to and have virtually become one with the alveoli. The flow of oxygen molecules -- the milk -- flowing forth from the "udder" of the respiratory bronchioles (cows) exit the bronchial tree and enter into the deoxygenated blood -- the soma juice -- carried by the capillaries. This is the "mixing" (upaparcana) referred to in the passages from the primary texts. But, at the same time as the happening of this blending -- of "soma juice" (deoxygenated blood) with "milk" (flow of oxygen molecules), there also takes place another movement of molecules. Carbon dioxide inherent in the deoxygenated blood exfiltrates through the membrane of the alveolus. This must be the "filtering of the soma juice" referred to in the text. The alveolus, it seems, in yet another addition to our ever burgeoning list of mystical animals, is sheep! And its membrane is its skin (wool?). Or it may be that it is the alveolar duct that is the sheep and the alveoli are merely its wool!

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