Aapa mahabhoota:

(jala) mahabhoota is next evolved from agni. Sense of taste (rasa) is its main sense attribute and liquidity (dravatva) is the basic property.  Aapa mahabhoota is the main constituent of the biological humor kapha dosha. Bringing and keeping two or more things together is possible because of this mahabhoota. Conceptually all biological, chemical and bio-chemical bonds are possible because of this mahabhoota. The cells of organs, particles of herbs and minerals are kept together by the vertue of this mahabhoota.