NO. 522] SHORTER ARTICLES AND DISCUSSION 377 



of ejection they were easily distinguishable, being ejected to a 

 less distance and rapidly inclining toward the bottom. The 

 spermatozoa, mi the other hand, remained floating for an hour 

 or more after the discharge had ceased. The operation went on 

 for a period of some thirty or forty minutes, and then ceased 

 almost as suddenly as it had begun. Within an hour or so the 

 water had cleared of its milky aspect, the cells having settled 

 to the bottom of the tank. 



The phenomenon was unlike anything which I had ever seen 

 among annelids. A single specimen would discharge at brief 

 intervals in jets like puffs of steam from an engine, and at the 

 height of the performance, when at least fifty specimens were 

 thus engaged, it was a spectacle of the most striking and exciting 

 character. If one could imagine some Lilliputian fire brigade of 

 similar numbers all intent on discharging intermittent streams 

 upon a miniature conflagration the impression could hardly be 

 more engaging! 



Antecedent Behavior. — It had been observed at the time of the 

 transfer of the specimens referred to above, that there were quite 

 a number of lame specimens which did not retract fully into the 

 tubes, as is usually the case under such an operation. This as- 

 pect was more or less persistent during the opera t ion of handling. 



tinue even after they had been put quietly into the aquarium. 

 It was this peculiarity which was engaging my attention at the 

 time the sexual explosions began. The query arose as to 

 whether it might not have been induced by some stimulus associ- 

 ated with the process of transfer and consequent exposure to 

 extraneous conditions. Accordingly I took occasion to subject 

 the colony to similar handling on subsequent days in order to 

 assure myself concerning the matter. But in no case was it 

 possible to induce a second discharge, or any simulation of the 

 sort. It seems highly probable, therefore, that the phenomenon 

 was perfectly normal, notwithstanding its apparently unusual 

 character. During the several years in which I had similar 

 colonies under observation in the same room for long periods it 

 would seem as if some symptom of the sort might have been 



