When the adhesive forces between liquid ands solid are larger than the liquid's cohesive forces, the meniscus in a small diameter tube will tend to be concave, for example water in glass.  This is because the resulting small contact angle will tend to "wet" the surface of the glass. (You can observe this with a straw and a cup of soda.)

If adhesive forces are smaller than cohesive forces the meniscus will tend to be convex, for example mercury in glass.