This section is from the book "The Practice Of Palmistry For Professional Purposes", by C. de Saint-Germain. Also available from Amazon: The Practice of Palmistry for Professional Purposes.
Some of the Main Lines are very frequently altogether absent from the hand; seldom, however, are the same Main Lines absent from both hands. In order of frequency - or infrequency rather - I would say that of the Six Chief Lines,
The Line of Life is never absent.
The Line of Head very rarely, even if it be only present in embryo.
The Line of Heart, seldom. Whenever it happens: a very grave omen.
The Line of Fate and the Line of the Sun, more frequently, although one of the two is fairly certain to take the place of the other. As the reader will be told later, these two lines are often considered sister lines and replace each other quite satisfactorily.
The Line of Liver is often absent; and many prominent Palmists consider its absence as a boon. I'll discuss the question at length in its proper place.
The first bracelet of the Rascette is always there. The second bracelet, often; the third,, seldom, at least in a clear, satisfactory shape.
The Line of Intuition and the Via Lasciva, being simply modifications, or at most, sister lines, of the Line of Liver, their absence is of no particular consequence.
The Line of Mars is rare - at least in its entirety.
The absence of the Girdle of Venus - happily very frequent - is quite desirable.
As to the Lines of Union, it is my experience that, at least one is found in every hand. I do not remember more than three exceptions to this statement.
And now that I have rapidly surveyed the principal characteristics of the Fottr-tecn Main Lines - distinguishing emphatically betweeen the Six Chief Lines and the Eight Minor Main Lines, I shall undertake, with the kind reader at my elbow, and plenty of illustrations to lighten up my path, the minute description of, and the many readings concerning this queen among Chief Lines - the Line of Life, preceding it, however, by my theory of Dates and how to discover them on the Lines of Life, Fate, etc. As soon as I enter the study of the Lines I have frequent occasion to refer to this theory; it is necessary therefore to present it as a sort of general introduction to the Lines.