328 
PACIFIC SCIENCE, Vol. XVII, Inly 1963 
SUMMARY 
A simple device for taking time-lapse pho- 
tomicrographs of a group of cultures of eggs 
to show the development of each individual 
has been described. This device is made of 
readily available material. It consists of two 
parts: (1) A piece of plate glass supported 
by a frame which is steady and independent 
of the motion of the photomicrographic appara- 
tus. It serves to replace the stage of the micro- 
scope and to carry the eggs in cultures in a 
motion-free state. (2) A carriage for the pho- 
tomicrographic apparatus which can be made 
to travel back and forth in a straight line from 
left to right, repeatedly bringing the micro- 
scope and its camera to a specific field in each 
culture for sequential photomicrography. 
The device has the advantage of being sim- 
ple, easy to construct and operate, and it can 
be used to follow photographically an individ- 
ual egg during its early development from zy- 
gote to morula as well as to record the appear- 
ance, disappearance, or persistence of develop- 
mental abnormalities. Other recurring phe- 
nomena can also be studied photomicrograph- 
ically by this instrument. 
REFERENCES 
Blum, H. F., and J. P. Price. 1950. Delay of 
cleavage of the Arbacia egg by ultraviolet 
radiation. J. Gen. Phys. 33:285-304. 
Hsiao, S. C., and P. C. Daniel. I960. Studies 
on the effect of ionizing radiation upon de- 
veloping sea urchin. Anat. Rec. 137: 365. 
Gray, P. 1958. Handbook of Basic Microtech- 
nique. McGraw-Hill Book Co., New York. 
Pp. 24-39. 
Shillaber, C. P. 1944. Photomicrograph in 
Theory and Practice. John Wiley & Sons, 
New York. 
