This is a very favorite and comprehensive symbol. Its spheroidal shape and its function as a life-germ are alike emblematic, and are connected with each other, as will appear. Our Easter is largely made up from an ancient North European festival of rebirth, which was celebrated in Spring, which is the appropriate time of year for such a festival, as it is then that nature comes to new life. It was not the birth of the year that was celebrated; it was rebirth in general, but that particular time was chosen as being most fitting. The egg is of course a familiar accompaniment of Easter celebration, and has not much to do with the ecclesiastical side of the festival, as far as one can see. But scholars will tell us that the egg was used by others besides the Northern peoples and their Christianized successors, and that it has been universally venerated as a sacred symbol, many people refraining from eating it on that account.
The Egg stands for that primordial Chaos, that Great Deep, Waters of Space, etc., mentioned in cosmogonies as being the great womb of Nature, the Virgin Mother, out of which the universe is produced by the fructifying breath of Divine Spirit. But again, the same symbol is used to denote the universe thus produced, and in this sense it is spoken of as the Mundane Egg or World-Egg. The comparison of the universe with a great egg is a most profound and apt analogy, and is naturally to be found in all cosmogonies. The spheroidal shape is that of all the worlds that revolve in space, as also the shape of eggs, seeds, and germs in general, drops of water, and many other things. It is the most comprehensive of all shapes and the most perfect and yet simple of forms, produced by an exact balance of forces expansive and contractile and equal in all directions. Cosmogonies usually go on to describe the splitting of this egg into parts representing the heavens and the earth, etc., and the respective symbolism of shell, white, and yolk. Within the egg is the germinal point; and by studying the anatomy and physiology of the egg before fructification, and the various stages of development of the embryo after fructification, much can be learnt about universal law by analogical reasoning. The development of the egg is actually a repetition of the entire cosmic process by which worlds and living beings are created. Can this be merely an interesting analogy, an accidental coincidence? No; for the same laws pervade the whole universe, as a whole, in its greater parts, and down to its minutest subdivisions; and there is not a living being, however minute and apparently inert, but is following those laws of development, at one stage or another. The body of man himself is born from an egg, though this is developed internally, instead of being dropped as is the case with fowls. A seed may be called an egg — the difference is little more than a question of names.
So the egg stands as symbol of that most comprehensive of laws with which Theosophy deals — universal self-evolution. The universe is a vast aggregate of living beings, all of which are evolving, each according to its own particular stage in the vast process, and according to the particular cosmic hierarchy to which it may belong. And the process is one of self-directed evolution from within. A mechanical doctrine of evolution tries to represent it as a process of accretion or adding together of parts; but that would not be evolution, not natural growth. Such a process would result in a chaotic mass of unorganised fragments; evolution demands that there should be a plan on which to build. That plan is contained in the germ within the egg. Biologists can watch the actual process taking place; but, though they see the scenes shifting, they cannot with their microscopes discern the scene-shifters.
All we can see with the microscope is the builders as they emerge from invisibility; the life-forces at the moment when they enter upon the plane of physical matter. We can trace things back to a minute speck, and no farther. That minute germinal speck is the point where the forces enter the physical plane. There is an ancient saying that omne vivum ex ovo, and since the universe is composed entirely of living beings, the egg must be omnipresent as being the germinal form of every organism, whatever natural kingdom it may belong to. In the numerical symbology of the Secret Doctrine the cipher is sometimes called the egg, which it resembles in its shape; and this, taken with the straight stroke, representing the fecundating principle, makes the sign for the number ten (10). The zero does not imply mere nihility — an utterly untenable idea — but simply the absence of number; it is "no number"; so that the circle represents the universe in an unmanifested state, which to our conceptions appears as nothing, though it is all.