Previously I mentioned some eggs that a local breeder of Cynolebias nigripinnis stored in glasses under mud from Feb. 1957 to Feb. 1959. In order to go on studying these eggs I took 100 transparent eggs and stored them very fine and dirty mud in a 200 ml glass with airtight lid on. Glass was stored in the dark at 20-24 C. Much gas developed that pressed off the lid several times, but as the layer of dirty mud was more than 2 inches high, I think no oxygen reached the bottom of the glass where the eggs were. The glass was completely filled with water over the mud. On 31 Jan. 1960, I washed the mud and found 17 transparent eggs and several burst eggs. The transparent eggs looked fine and newly laid. These eggs were placed in a glass with clean water and no mud. Now after about 40 days, 5 are still transparent, but no embryo can be seen inside the eggs. However, the conditions of storing were very severe in this case. H2S is very poisonous.