thoughts…
Spheres on top, and top development in contrast to the ground, earth, signifies the ego development of something, the evolution away from x, or the ground. For a human, the head is the furthest most point from the ground, evolving away from the earth. In plants the flower and bulbs, are the most evolved away from the ground. The evolved aspect in a being will have two poles, the most evolved, escape velocity evolved = the head; and the closer evolved, the parabolic evolved, the seeds. The testes on a male, and the ovaries on a female are the most parabolic evolved (involution), earth related evolved portions of that being. In plants it is the seeds.
If you go into a head stand on the ground, on the earth, the most ego, the most evolved away, will once again feel included, as the lower body pressures the bulb (head) against the earth, and the living portion of the most evolved has a chance for renewal, in harmony with earth, the ground.
Plant the head (the most evolved) in the ground and death occurs. Plant the seed in the ground, and a new plant arises.