3O E. E. JUST. 



2:15 P.M. 8 c.c. of sea-water pipetted from the Echinarachnius eggs and filtered 

 (8 c.c. of sea-water added to the eggs). 2:00 to 4:00 P.M. This egg-water re- 

 moved (second washing) gave on Echinarachnius sperm a i6-second reaction at 

 1/12,800 dilution. It failed to agglutinate Arbacia sperm but activated them very 

 intensely. Arbacia egg-water on these same sperm gave an 8-second reaction on 

 1/6,400 dilution. 



July 16. A strong Echinarachnius egg-water, 1/12,800 power, tested on Arbacia 

 sperm gave no agglutination, but very intense activation. 



The experiments here cited represent but a small percentage 

 of the total number made with Echinarachnius egg-water on 

 Arbacia sperm. There can thus be no question as to the failure 

 of the Echinarachnius egg- water to agglutinate Arbacia sperm. 

 On the other hand, the stimulation to increased motility in- 

 duced by Echinarachnius egg-water is very remarkable. 1 In 

 no other case that I know is the activation so marked. It will 

 be noted that the egg-water used is that charged either by thor- 

 oughly washed "ovary eggs" or by dry eggs; this, a fact which 

 may be significant, must mean that such sea-water contains very 

 little if any perivisceral fluid. 



2. Effect of Arbacia Secretion on Echinarachnius Sperm. 



Sea-water charged by Arbacia eggs with an agglutinating 

 substance for Arbacia sperm likewise contains a substance that 

 agglutinates Echinarachnius sperm. Certain characters of this 

 agglutination of Echinarachnius sperm show that it is due to a 

 hetero-agglutinin distinct from the Arbacia sperm agglutinin. 



(a) Agglutinative Power of Arbacia Egg-water on Echinarach- 

 nius Sperm after Successive Dilution. In the first place it may 

 be noted that on dilution of Arbacia egg- water the agglutinating 

 substance for Echinarachnius sperm drops out before the agglu- 

 tinin for Arbacia sperm. A freshly prepared suspension made 

 of unwashed "ovary eggs" may agglutinate Echinarachnius 

 sperm in a very powerful manner, irreversibly so in some cases; 

 but if the egg-water stand or be diluted this effect will gradually 

 disappear, the iso-agglutinin remaining. On the other hand, a 

 suspension of shed eggs not uncommonly gives no agglutinin for 

 Echinarachnius sperm, though this class of eggs most actively 

 secrete iso-agglutinin. 



1 Asterias sperm exhibit an interesting phenomenon. When a fresh suspension 

 is prepared, the sperm may be absolutely immobile and remain thus. If now they 

 be mixed with eggs inseminated within one or two minutes previously, they are 

 stimulated to great activity so that they may roll the eggs around. 



