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 gyroscope is mounted in a sphere, lined with Mu-metal to reduce magnetic influence, connected by a spindle to the vertical axis of the theodolite. The battery-powered gyro wheel is rotated at 20,000 rpm or more, until it acts as a north-seeking gyroscope. A separate optical system within the attachment permits the operator to rotate the theodolite and thereby bring a zero mark on the attachment into coincidence with the gyroscope spin axis.