The human foetus after about 2 months development, surrounded by the amniotic sac (which remains filled with fluid throughout the term of pregnancy, forming a protective barrier around the developing embryo). The embryo is seen from the rear, with the head at left & the formative buds of the arms & legs visible. At this time the primitive organ systems are almost fully developed: the 3 initial divisions of the fore-, mid-, & hindbrain have become 5 divisions and further growth has caused the head to bend over. Spinal nerves grow out from the spinal cord, connecting with body organs as they are being formed.