Results and Discussion:

At second cleavage, all the eggs that were radiated with UV for one minute looked normal. At second cleavage,

most of the eggs that were radiated with UV for two minutes looked normal. A couple of eggs looked like Figure 2. They

had a cytoplasmic blip. At second cleavage, majority of the eggs that were radiated with UV for five minutes looked

normal. A handful of eggs looked the same as Figure 2. The UV did not seem to damage the embryos immediately; most

of the second cleavages were normal for all eggs in all the experimental exposure times.

In the second part of the experiment, the embryos were observed after gastrulation. At that point the archenteron

is visible, secondary mesenchyme cells are visible, and cells organized themselves into spicules. All the control eggs

were hatched from the fertilization envelope and were ciliated as in Figure 3. All the embryos that were radiated with UV

for one minute had blastula and cilia and primary mesenchyme cells but no vegetal plate or vagination was observed.

This is seen in Figure 4. All the embryos that were radiated with UV for two minutes looked the same as Figure 4 except

one normal embryo was found. All the cells that were radiated with UV for five minutes looked the same as Figure 4. All

the abnormal embryos had abnormally large amounts of cells in the blastocoel. All the cells radiated with UV-C seem

delayed in development or dead at the beginning of development of the vegetal plate. Most embryos did not undergo

gastrulation. The UV-C damages the embryos somewhere between the second cleavage and gastrulation. The amount of