Embryo implantation in humans. After fertilization the human embryo begins a 4 day long journey down the fallopian tube and into the uterus. When the embryo reaches the blastocyst stage it develops two distinct populations of cells. The outer cell mass,called the trophectoderm, and the inner cell mass.
Cat eye glasses. Named after their resemblance to the shape of a cat's eye, cat eye glasses are probably the most popular style of vintage eyeglasses. Though cat eye glasses were around since the 1950's, they reached their peak popularity when Audrey Hepburn wore a pair in the 1961 film Breakfast at Tiffany's.
The term cat's eye derives from the resemblance of the cat's eye retroreflector to the optical system that produces the well-known phenomenon of glowing eyes or eyeshine in cats and other vertebrates (which are only reflecting light, rather than actually glowing).n alternative form of the cat's eye retroreflector uses a normal lens focused onto a curved mirror rather than a transparent sphere, though this type is much more limited in the range of incident angles over which it retroreflects.