﻿176 Proceedings of the Royal Physical Society. 



had been living some months in the tanks of the ^lillport 

 Marine Station, and was harbouring two species of nematode, 

 a large number of a species of trematode, and a trypanosome 

 as well as Icthyosporiclium. 



The alimentary tract showed a very marked reaction to 

 the presence of the Ictkyosporiclium. The liver was of a 

 dull ochre colour, with numerous small hard lumps. The 

 part of the liver where these lumps were most numerous 

 was bright green. The intestine showed thickenings of the 

 wall in places, and several cfecal outgrowths of about J to 

 1 cm. in length. The spleen was considerably enlarged, but 

 otherwise normal. 



The condition of the alimentary tract, and also the appear- 

 ance of the parasite in the live state, suggested at first that 

 I was dealing with Lymphocystis johnstonei, described by 

 Woodcock.^ Further investigation, however, showed that the 

 form in question differed in the most essential feature from 

 that described by Woodcock. Thus Lym-phocystis is said to 

 possess a single ill-defined nucleus, whereas Icthyosrporicl/him 

 is certainly, in all the stages which I have observed, a multi- 

 nuclear organism with small but very definite nuclei of a 

 quite characteristic protozoon type. 



The parasite did not lend itself to investigation in the 

 live state, so parts of the liver were fixed in corrosive 

 sublimate solution and in Flemming's fluid, and cut into 

 thin serial sections. A variety of stains were used : — 

 Heidenhain's iron haematoxylin, Ehrlich's hsematoxylin, 

 thionin, and eosine saturated solution in 70 per cent, alcohol, 

 followed by 1 per cent, aqueous methylene blue. The best 

 of these was Ehrlich's haematoxylin, and next to it the eosine 

 and methylene blue. Thionin stained the protoplasm too 

 deeply, and Heidenhain seemed very difficult to control, 

 and rather untrustworthy. 



The intestine was also cut into thin sections, and gave 

 some interestino- results, though the material was not 

 histologically in so good a condition, as it had been fixed 

 for the most part in picroformol, and not quite sufficiently 

 carefully treated in the washing out. 



^ Tra'ds. Liverjpool Biol. Soc, vol. xviii,, Session 1903-1904, p. 143. 



