Golgi apparatus. Transmission electron micrograph of a Golgi apparatus in a frog leucocyte (white blood cell). The Golgi apparatus is a system of membranes and vesicles that packages proteins and lipids produced by the cell for export outside. The white circles seen here are vesicles that have budded off from the Golgi apparatus. The dark area at the top is the cell nucleus, bound by the nuclear membrane. The grey disks at the bottom are energy-producing mitochondria. The dark circle close to the Golgi apparatus is a centriole, a cylindrical body (seen here in section) involved in organising chromosomes during cell division. Magnification x85,000 at 10x8 inch size.