Distribution, Food and reproductive Capacity of some fresh-water Amphipods. 13 



original dishes. It was observed that if these eggs were so treated 

 within four or five days of the date of hatching they would continue 

 to develop normally and hatch in approximately the some time as those 

 that remained in the brood pouches. 



Even though a great many trials were made only scanty data 

 were forthcoming. A large number of failures were due to the untimely 

 disappearance of the females within a few days after oviposition. This 

 was finally overcome by separating the sexes as soon as possible after 

 the appearance of eggs in the brood pouch. No male was caught in 

 that act of killing its mate but the circumstantial evidence of murder 

 was very strong. 



Table V. 



6. The Young: Activities and Relation to Parent. 



The newly hatched young vary in size as indicated in table XI, 

 p. 23. There is a noticable difference in the degree of activity bet- 

 ween those of G. limnaeus und E. gracilis. Immediately after hatching 

 the former are capable swimmers. Generally those under observation^) 

 swam about the watch glass until they collided with some aquatic 

 plant and if the plant happened to be a specimen of Elodea, Myrio- 

 phyllum or Utricularia, the young would begin to climb up the 

 stem into the axils of the leaves or into the infolding leaf bud. Here 

 they would rest or begin to feed. Many arose to the surface only to 

 climb among the rhizoids of a floating liverwort (Ricciocarpus). These 

 rhizoids not only constituted a safe retreat for the young but also 

 furnished in themselves tender plant food for which the former ex- 

 hibited a strong desire. Other young crawled underneath bits of dead 

 leaves and bottom rubbish. In other aquaria the young, even when 

 nearly mature, burrowed out of sight in the bottom sediment consisting 



^) These young amphipods were hatched from eggs which had previously been 

 taken from females and isolated in watch glasses. 



