72 PRACTICAL PABASITOLOGY 



Both the mature forms and the motile young forms should be studied, 

 and the oocysts should be sought for. These, as in Adelea ovata, 

 undergo the entire process of sporogony within the body of their host. 

 They are round in shape, and the soft body, which in the unicellular 

 stage is known as a " sporont," divides into numerous sporoblasts 

 which, by the secretion of an envelope, become changed into " sporo- 

 cysts." These are likewise round, and within them five to six sporo- 

 zoites are formed, leaving a small residual body. 



The early stages of the process of fertilization are more easily seen 

 in Klossia than in the Eimeria, the copulation or merging of the 

 gametes being preceded by a conjugation or transitory attachment of 

 the immature gametocytes. It is only after conjugation has taken 

 place that the microgametocyte, which is smaller than the macro- 

 gametocyte, divides into four microgametes, one of which completes 

 the fertilization of the macrogamete, which has, in the meantime, 

 become mature by reduction of the nucleus. A similar process is 

 performed by Adelea ovata in the intestine of Lithobius. 



Cover-glass preparations are made by passing a cut surface of the 

 infected kidney under gentle pressure over a cover-glass. They should 

 be fixed and stained in the same way as preparations of the Coccides 

 of the centipede. Or thionin may be used for colouring, as it is par- 

 ticularly successful in showing the granulations of the protoplasm. 



The examination of sections is very instructive. For these, the 

 kidney should be fixed whole in alcoholic solution of mercuric chloride, 

 or in Flemming's or Hermann's mixture. If the sublimate solution 

 is used they should be coloured with hsematoxylin, but with safranin 

 after fixing with mixtures containing osmium. The epithelium of the 

 kidney consists of a single layer of cells ; it projects from the kidney 

 wall into the interior of the organ in numerous folds which are sap- 

 ported by lamellae of connective tissue. These folds are arranged in 

 such a way as to occupy the hollow space in the interior of the organ. 

 The parasites are found in the enlarged cells of the glands, and they 

 are generally united in groups. 



(c) Coccidia found in the Liver of the Rabbit. 



The coccidiosis of rabbits is epizootic in its occurrence, and usually 

 affects the young rabbits of a stock. As a general rule, only old 

 healed-up knots are found in the livers of old animals. Infection is 

 established in the case of the living animal by the presence of oocysts 

 in the dung. Fresh material being somewhat difficult to obtain, it is 

 generally necessary to rely on fixed and coloured specimens. 



The parasites invariably belong to one species, namely, Eimeria 

 stiedce (Lindem.), and are found in both the liver and the intestines. 

 The changes which take place in the liver are particularly interesting. 



