4 ART. 4. — N. YATSU : 



on July 28tli (21st of the lunar calendar), Mr. Moeiwaki came 

 and told me, that he saw in the howl yellow dust which was 

 perhaps eggs. At this information I hastened into the room and 

 to my great joy, I found that the yellow dust was nothing other 

 than the sexual elements. This was prohahly the first instance 

 in which the spawning of the Ecardines has been observed. 



Four individuals of the maximum size, two males and two 

 females, were discharging their sexual elements. The eggs were 

 of an yellow color and so small that we could hardly distinguish 

 them individually with the naked eye. They were forcibl} r dis- 

 charged from the median funnel of setae like a jet of water. As 

 the clouds of eggs came out constantly during the spawning, they 

 assumed the form of an inverted cone, ascended nearly perpen- 

 dicularly to the surface of water and then gradually sank to the 

 bottom. The process appeared like the eruption of a miniature 

 volcano. After a few minutes the spawning ceased. The fallen 

 eggs covered in a tolerably thick layer an area of some thirty 

 square centimeters. As some mucus was secreted from the mantle 

 at spawning, the egg-layer was found to be like a scum, when I 

 tried to dip the eggs up with a pipette. Sperm was emitted in 

 the same manner as the eggs, but it was milky white in color. 

 In nature these elements discharged simultaneously are no doubt 

 mixed up by the current and fertilization is thus secured. 



As I did not witness the beginning of the process of spawn- 

 ing I am unable to say which sexual element was the first to be 

 discharged. But the following hypothesis would not be incredible. 

 Until the sperm is .discharged the eggs even when well ripened 

 seem to be retained within the body. When the sperm is emitted 

 some chemical substances discharged in the spermatic fluid may 

 diffuse in the water and irritate the female, thus awakening the 



