Reproduction in Sagitta Elegans 



105 



Seasonal occurrence of the eggs in the plankton, and the proportions of the various develop- 

 meyital stages throughout the season. 



TABLE II. 



* The numbers refer to the standard grades in fineness of bolting cloth as given 

 by Dufour & Co. 



the eggs classified accordingly. Stage 1 included all eggs with embryos 

 varying in development from the single cell to the gastrula; stage 2 from 

 the initial elongation to the single coil; stage 3 from that point to the 

 final double-coiled embryo. At this station the proportions of stage 1 

 decreased and those of stage 3 increased until the disappearance of the 

 eggs. Small Sagittae, down to 2 mm. in length appeared at the end of 

 May and were still found up to the middle of June, but at the end of 

 June there was none smaller than 4 mm., and on July 11 the smallest 



