294 E. A. MINCHIN. 



In none of the Holothurians studied by me at Naples was 

 I so fortunate as to find any cysts. Other work prevented 

 me from giving as much time to these interesting organisms 

 as I could have wished. I have^ therefore, only the material 

 to go upon which I found in the specimen of Holothuria 

 t ubulosa from Naples, supplied for dissection at Oxford. In 

 this specimen the body- cavity contained numerous spherical 

 cysts floating free in the body-cavity, each containing an opaque 

 central spherical mass, usually placed slightly excentrically. 

 The diameter of the cysts varied from about 6i0 /z to 820 /u, 

 and the diameter of the internal opaque sphere from about 

 550 fx to 590 ju. The difference between these two measure- 

 ments gives the thickness of the jelly envelope. I found in all 

 cases the cysts perfectly smooth, and am astonished that Min- 

 GAZziNi (5, 314) gives a characteristic of the genus that the 

 wall of the cyst is covered with little spines. I have observed 



JoH., " Ueber einige Argentiuische Gregarinen, &c." (' Jena. Zeitschr. f, 

 Naturwiss.,' xxvii, pp. 233—336, Taf, viii), which only came into my hands 

 after my paper was finished. The memoir in question, which describes five 

 new Poljcystids from Argentine hosts, being mostly filled with details of the 

 microchemical analysis of these animals, contains little which I need notice 

 here with the exception of the peculiar structure of the nuclei iu some of 

 the forms. In Gregarina statirse, G. bergi, G. pauchlorae, and 

 the young form of Pyxinia crystalligera, the nucleus is described as 

 possessing a peculiar nucleolus, which the author terms a "morulite." This 

 body is described in G. statirse as "having a peculiar dull shine [eigentiim- 

 lich triibe glanzend] with a feebly yellowish light, and being in addition 

 rough, with warty wrinkles on the surface just as in many other Protozoa, and 

 especially Rhizopoda (amcebse), on which account it is usually termed mul- 

 berry-like." It reacts like nuclein, but is specialised to resist digestion, and 

 hence its substance may be termed " morulin" (p. 270). 



It seemed to me at first that this might be a vacuolar nucleolus, like those 

 in my Gregarines ; but as this could only be made out by very thin sections, 

 a method which Frenzel docs not seem to have practised, this point cannot be 

 determined. 



By treatment with concentrated acetic acid a delicate widc-meshed network 

 arises in the nucleus, which before appeared homogeneous. In strong nitric 

 acid the morulite slowly vanishes, and only the network is left. It seems to 

 me not impossible that this network is an artificial coagulation of the 

 " Kernsaft." 



