Abstract: An internal information detector is disclosed, which is capable of preventing the leakage of pressure from an attached portion to a pressure vessel, and also preventing the interference with the pressure vessel. This internal information detector comprises a pressure injection valve penetrating a partition wall of the rotatable pressure vessel, the pressure injection valve being fixed to the pressure vessel; and an information detection unit located in the pressure vessel to detect information inside the vessel, the information detection unit being united with the pressure injection valve. The position of a center of gravity is adjusted to cancel a rotation moment caused by a centrifugal force during the rotation of the pressure vessel.

Abstract: Cryopreservation of primordial germ cells and germ cells, in which primordial germ cells or germ cells are separated from bird embryos before meiosis and are then suspended and frozen in a freezing medium containing a cryoprotective agent is useful for the conservation of species of birds, for the protection of rare species which are in danger of extinction and also for the production of transgenic animals, the production of novel animals having gene markers on a cellular level, the production of animals useful as disease models, the production of useful substances by genetic engineering, and the development of test methods for toxicity to germ-line cells.

Abstract: A fertilized ovum is recovered from an upper portion of a magnum of an oviduct of a dead hen 60 to 80 minutes after oviposition. The fertilized ovum is placed in a container containing a thin albumen. A yolk of the ovum is covered with a sheet of gauze, and the ovum is cultured up to the blastoderm stage (stage X) in the container which is covered with a sheet of plastic film that is held by a rubber band.