A] 
of electron microscope imagery and Mannen (1964, 1966a, 1966b and 
1968) demonstrated the use of a conventional stereomicroscope for 
three-dimensional measurement of nerve cells which resulted in some 
striking neuronal contour maps. Ueno (1969), a co-worker of Mannen, 
went on to give details of an experimental stereophotogrammetric 
microscope for contouring at intervals down to a few micrometers. 
Marraud (1955), Haanstra (1966), Boyde (1967, 1968. 1970, 
1971), Aronson et al (1970), Oshima et al (1970) and Howell (1972 
have also reported stereophotogrammetric measurements with the 
electron microscope in various industrial and biological studies. 
Eick and co-workers (1971a and 1971b) have focused attention on 
scanning electron microscopic stereophotogrammetry in the dental field 
and Ghosh (1971) has compiled a contour map of a human blood cell 
using stereo images obtained through a scanning electron 
microscope——values of 19-24.5 cubic rnicrometers were obtained for the 
cell volume and 1.2-2.3 cubic micrometers for the volume of the 
platelet, using three different methods of computation. 
4. FOUR-DIMENSIONAL STEREOPHOTOGRAMMETRY 
When a body part grows or moves, it changes its position in space 
time and since all body structures are three-dimensional, growth and 
movement involve a total of four dimensions——the fourth being time. 
The movement of a heart or an eye can occur in a fraction of a second, 
but changes due to growth can extend over a period of many years. 
Photogrammetry has been used to explore four-dimensional biomedical 
phenomena ranging from the rapid to the slow changing variety. 
^ 
Etienne Marey (1894), the famous French physiologist, ascribed 
"one of the very first applications of photograpy" to Onimus and 
Martin. In 1865, they exposed the heart of a living animal and took a 
time-lapse photograph of it by leaving the lens uncovered. The 
photograph was found to have a double outline representing the two 
extreme positions of contraction and dilatation. Since that time, 
monophotogrammetry has been used extensively in medicine and 
biology for measuring change of. one type or another, but we will 
confine ourselves here to true stereophotogrammetric investigations of 
which perhaps the first can be attributed to Marey himself. In 1894, he 
published a stereopair showing the path taken by a point on a man's 
lower back as the individual walked away from the camera. A year later, 
Braune and Fischer (1895) reported using four cameras simultaneously 
to study three-dimensional aspects of gait. Their method was simplified 
by the Russian, Bernstein (1927) who used a mirror to obtain two 
distinct points of view with a single camera and a single rotating shutter. 
With this setup he produced the first examples of three-dimensional 
“cyclography.”