BLOOD-PARAS ITKS OF PISHES OOCUEEINO AT EOVIGNO. 115 



or movement in these intra-cellular forms so long as they 

 were kept under notice, but in a few of the living preparations 

 one or two small foi'ms were seen free. These in all proba- 

 bility corresponded to the small intra-cellular parasites. They 

 appeared as sausage-shaped bodies very slightly curved. One 

 third or so of the body was granular in character ; this prob- 

 ably was the region of the nucleus (cf. description of fixed 

 and stained parasites below). They underwent no active 

 displacement, and it was difficult to feel sure whether they 

 really moved or altered in shape at all or not. Now and 

 again the concavity would appear to lie first on one side of 

 the body and then on the other, and now and then the body 

 would stand on one end, appearing in transverse optical sec- 

 tion as a round globule; but these changes were extremely 

 slow, and may have been due to passive rotation of the vermi- 

 cule, caused by very delicate currents in the blood-plasma at 

 that spot, not sufficient to disturb the corpuscles. As we did 

 not see any intra-cellular forms actively liberating themselves 

 fi'om the corpuscle, it may possibly be that these free indi- 

 viduals were accidentally liberated by the rupture of the 

 corpuscle during the process of manipulation, which would 

 explain their apparent immobility. In the stained smears 

 only one such free form has been found (fig. 3). 



In most of the permanent preparations made only a little 

 searching with the oil-immersion lens is required to find a 

 htemogregarine. The parasite does not appear to be in quite 

 the same period of its development in all three gurnards. In 

 gurnards 1 and 3 the htemogregarine is present chiefly or 

 almost entirely in the one phase — the small type. Large 

 forms (see below) do occur, but they are evidently very rare. 

 Two or three individuals of the latter type have been found 

 both in the general circulation (fishes 1 and 3) and in a 

 smear from the kidney (fish 1), but they have not been 

 observed in smears from the liver or spleen, and no other 

 phases have been seen in any of the organs. In fish 2, on 

 the other hand, in which the parasites are rather more 

 numerous, besides the small forms many large forms occur 



