SPOROCYSTS IN AN ANNELID.^ 



EDWIN LINTON, 

 Washington and Jefferson College, Washington, Pa. 



In the summer of 1910, while at work at the United States 

 Fisheries Biological Station, Woods Hole, Mass., I was told by 

 Dr. Gilman A. Drew that what were supposed to be cercarise 

 had been noticed at different times associated with the annelid 

 Hydroides dianthus Verrill among material being used for study 

 at the Marine Biological Laboratory. 



Acting upon this suggestion I examined a large number of these 

 serpulids on several dates in August of that year. Although 

 much of the material was examined very minutely, the worms 

 having been removed from the tubes, teased, and everything that 

 even remotely resembled a sporocyst further examined, neither 

 sporocysts nor cercariae were found. 



In the following summer I secured two lots of these sporocysts 

 from this annelid. For the first lot, July 15, I am indebted to 

 Dr. Drew, and for the second, July 21, to Miss Margaret Morris. 



In each case the single annelid was lying in a dish of sea water, 

 and in the bottom of the dish there were a large number of sporo- 

 cysts. These sporocysts were found to contain cercariae in 

 various stages of development but no rediae. As they lay free 

 in the sea water the sporocysts were for the most part white, or 

 bluish translucent white. In some of them there were varying 

 amounts of orange pigment of similar appearance to the abundant 

 pigment in the annelid. They were short and thick, bluntly 

 rounded at the ends, and more or less arcuate. In some cases 

 they were curved until the ends almost touched each other. 

 Many of the second lot were orange yellow, also many of them 

 were actively contractile. A frequent change of shape was that 

 from the characteristic short, blunt-pointed sub-cylindrical 

 form to a fusiform shape with elongated and slender-pointed 



1 Published by permission of Commissioner of Fisheries. 



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