EGG STRINGS IN COPEPODS — HEEGAARD 



233 



space between the partitions, thus leaving room for the subsequent 

 development of the larva. 



After the ejection of the eggs from a single loop of the oviduct, 

 the spawning female rests for a few minutes, during which period 

 peace also comes to the fish. In this period, however, vigorous peri- 

 staltic motions take place in the lower part of the oviduct through 



Fig. 2. — Caligus ciirtus (O. F. Miiller). Egg masses shed in culture dishes of 

 8 cm. in diameter with air bubbling through. The irregular arrangement is 

 clearly seen. Such egg masses will have no chance to develop. 



which new eggs are pushed forward until they fill the last bend near 

 the opening with eggs. New severe convulsive birth pangs eject a 

 new group of eggs and again start the fish leaping forward in the 

 water. 



At the end of each egg-laying performance both the copepod and 

 the fish are exhausted, resulting, especially in captivity, in weak leaps 

 of the fish during subsequent egg layings. This in turn results in 

 egg strings that are not fully drawn out, as shown in figure i. In 



