Ferns Edit. In most ferns, gametophyte is a photosynthetic free living organism called a prothallus. For example, in the leptosporangiate fern Dryopteris, the gametophyte is a free-living, autotrophic prothallus that produces gametes and maintains the sporophyte during its early multicellular development.
It is therefore an object of the present invention to provide a gyro stabilized center tracking vehicle, of reduced complexity in which the gyro Spin axis is maintained in its normal position by forces reacting against the earth, and in which these forces are minimized by torquing the gyro frame about its pivot axis.nother object of the invention is to provide a gyro stabilized center-tracking trail vehicle in which a gravity sensitive mass applies a torque to the gyro frame in a direction to erect the vehicle upon tilt from a vertical or plumb line attitude.
A pair of Deployable Universal Combat Earthmover (DEUCE) bulldozers working in tandem. The DEUCE program began in late 1992, when the U.S. Army Engineering School (USAES), Fort Leonard Wood, MO, began exploring the concept of an air-transportable, self-deployable, low velocity air-droppable dozer for light infantry and Airborne units.