The ovulation related phenomenon of saliva crystallization in a fern-like pattern was first observed in 1957 by Andreoli and Della Porta from University in Torino . J.M.Biel Casals (Casals J.M.B., 1968) was the first to investigate this phenomenon more extensively. He examined 493 saliva samples and concluded that the intensity of crystallization is directly dependent on closeness of ovulation. The method used for determination of crystallization is simple: a drop of saliva is placed on a glass slide and left to dry at the room temperature. When completely dry, the sample is examined using small magnification.

Salivation (Gayton C.A.,1981)

Main salivary glands are: parotid, submandibular and sublingual glands; there is also a lot of small buccal glands. Daily salivation ranges from 1000 to 1500 ml. Saliva consists of two kinds of secretion: (1) serosus, containing ptyalin, enzyme (alpha-amylases) for starch digestion , and (2) mucous secretion which protects and moists the oral cavity. The saliva pH is between 6.0 and 7.4 . Salivary glands are compound glands consisting of acinuses covered by secretory glandular cells and system of small ducts conducting saliva into the oral cavity.

The secretion of saliva takes place in two stages; at the first stage, acinuses and, at the second, ducts are involved. The acinuses secrete the so called primary secretion containing saliva enzymes in ionized solution which, as regard ions, does not considerably differ from plasma. However, the ion composition of the primary secretion is significantly modified in the ducts by two important active transportations.

In the first place, sodium ions are actively reabsorbed from excretory ducts and potassium ions are actively secreted in exchange. Accordingly, the concentration of sodium as well as chloride ions decreases while the concentration of potassium increases. Secondly, the bicarbonate ions are secreted into excretory ducts by way of enzyme carboanhydrasis that is in epithelial cells of excretory ducts. In exchange for bicarbonates, additional quantities of chloride ions are passively reabsorbed from excretory ducts . As a result of processes of active transportation , in conditions of rest, the concentration of sodium and chloride ions in saliva is about 15 mEq/lit each , being approximately 1/7 to 1/10 of their concentration of plasma. On the other hand, the concentration of potassium ions is about 30 mEq/lit being approximately 7 times higher than in plasma. The concentration of bicarbonate ions is about 50-90 mEq/lit , being 2 to 4 times higher than in plasma.

When saliva is been secreted more intensively, the concentration of ions in saliva considerably changes because the primary secrete in acinuses is secreted 20 times faster. That increase in fastness causes such an acceleration of the flow of the secrete through excretory ducts so that changes in its composition that occur during the passage take place to a considerably lesser extent than they otherwise do. Accordingly, when saliva is secreted more intensively, the concentration of NaCl is higher than usual and amounts to 1/2 to 2/3 of the one in plasma, while the concentration of potassium is lower than usual - only 4 times higher than in plasma.

Due to the fact that a concentration of potassium ions in saliva is high, any abnormal state accompanied by long-term hypersalivation can cause a serious loss of potassium ions and severe potassium defecit.