BLOOD-PARASITES OF FISHES OCCURRING AT ROVIGNO. 125 



unlikely that one or both of the grains at the edge of the 

 nucleus, on its inner side, may represent the same bodies. 

 Individuals which are somewhat larger, but still distinctly 

 intermediate in size, are seen in figs. 45 and 15, the former 

 being of the slender type, the latter of the broad type. 



We have not found any other phases of the hsemogregarine, 

 besides those above described, in our preparations. In the 

 gurnards from which smears of the internal organs were made 

 the parasites happened to be nearly all small forms, and 

 large forms are very scarce. In these cases, although pi-e- 

 parations from the liver, kidney and spleen have been searched, 

 no signs of schizogony have been noticed.^ Perhaps if smears 

 had been taken from these organs in the case of the gurnard 

 in Avhich the large types of form are frequent, multiplication 

 phases of a particular kind might have been found. 



It is important to note that we have never found any indivi- 

 duals of either of the large types free from the blood- 

 corpuscle. Further, in only a solitary instance has one of the 

 small forms been noticed free (fig. 3). This occurs on a smear 

 from the kidney. The parasite is not very vermicule-like, 

 and resembles the small intra-cellular type of form. This 

 scarcity of free forms quite agrees with our observations of 

 the parasites in the living condition (cf. above, p. 115). 



General Considerations. 



We have now to consider what is the sig-nificance of the 

 different phases observed, in what relation do they stand to 

 one another, and how do they compare with the known forms 

 of other htemogregarines ? 



The ordinary small forms doubtless represent an early 



1 The only possible indication of commencing schizogony which we 

 have noticed is found in two or three of the small forms in a prepara- 

 tion from the infected gurnard examined. The nucleus of the parasite 

 shows a constriction about the middle, which causes it to appear some- 

 what dimibbell-shaped (fig. 28). This may, perhaps, signify commencing 

 nuclear division, prior to fission of the parasite, but we do not feel at 

 all certain upon the point. 



