Can the shape of the palm be altered?

Cheiro says: `The shape and type of hands are mostly hereditary, whilst the lines, etc., are the result of external, astrological,cerebro-nervous, magnetic, and internal influences; "and to this opinion I agree, for the shape of the palm remains the same, although different kinds of employment, at mosphere, etc., may make it harder, or it may become thicker and softer by sedentary work or luxurious living, yet its inherent shape will remain intact.