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.
Gyrotheodolites are an older, but accurate way to find true north. They can be used on the Earth's surface, but these days they tend to be used for surveying underground, in tunneling and mining applications. GPS surveying methods are replacing gyrotheodolite methods for this application on the Earth's surface. Gyrotheodolites are surveying instruments composed of a gyroscope attached to a theodolite. There is more information about gyrotheodolites here. When used underground, they are the best way to establish the initial surveying reference points underground.