726 PROCEEDINGS OP THE ACADEMY OF [DeC. , 



nuclei, N. The cytoplasm of the cyst has a very diSerent staining 

 reaction from that of the egg, staining a faint violet with hoema- 

 toxylin-eosiu, and having a finely granular appearance. The 

 nucleus of the cyst, N.par., is irregular in outline, in some speci- 

 mens with amoiboid processes. It stains homogeneously a bright 

 red, hajmatoxylin-eosin, while the nucleoli are darker and fre- 

 quently vacuolated. 



The presence of the additional egg nuclei in the cytoplasm at 

 the base, of the cyst render it probable that the parasite entered 

 the cytoplasm when the ovum was in a syncytium. The presence 

 of the parasite may have caused an abnormal growth of the egg 

 cytoplasm, or the latter may have merely expanded with the growth 

 of the cyst. In its appearance the cytoplasm around the cyst is 

 like that of the normal, uninfected eggs. 



Figs. 48, 61, show two infected egg cells from a different indi- 

 vidual, with amoeboid, probably earlier stages of the parasite, 

 Par. In tiiis particular worm almost every Qgg has been infected. 



As a rule, the gonads of the male specimens that were studied 

 were not infected, but in a few worms the testes contained large 

 bodies that were evidently parasites, and that resembled some of 

 the stages found in the ovaries. 



The relation, if any exists, between the amoeboid masses found 

 in the intestine and those within the egg cells has not as yet been 

 worked out, as it is not within the scope of the present jjaper, 

 but in consideration of the prominence of these parasites and of 

 their position in the ova, this brief description has been given. If 

 sufficient material can be obtained for the intermediate stages, this 

 subject may later be studied in detail. 



The presence of adult Gregarines in Nemerteans has been 

 known for a long time, and they are mentioned and described by 

 several of the earlier Nemertean writers — Frey and Leuckart 

 (1847), Kolliker (1848) and Johnston (1865), Appendix, p. 290. 



I have found no references in literature to any structures quite 

 similar to those found in the ova of Zygeupolia. M'Intosh (1867) 

 and Wheeler (1896) describe parasites that have a certain degree 

 of likeness. 



M'Intosh found adult Gregarines in Borlasia octoculata = Lineus 

 sanguineus and Borlasia olivacea = Lineus gesserensis. Besides 

 the adult Gregarines, M'Intosh found what he called " certain 



