COCCIDIUM CUNICULI 761 



and leading to atrophy of the liver substance. The internal organs are wasted 

 and discoloured, the blood is pale-coloured and watery, and the animal eventually 

 dies. 



The Coccidium of the rabbit may infect man. Gubler has seen as many 

 as twenty purulent cysts in the human liver, of the size of a walnut or hen's 

 egg, in which the parasites were actively multiplying. In a case recorded by 

 Silcocks the liver, spleen and intestines were in- 

 fected, the parasite being found in all the lesions. 



The Coccidium described as Coccidium perforans 

 or G. hominis, and found in the epithelial cells of 

 the intestine of the rabbit and man, has now been 

 shown to be the same species as C. cuniculi (Rivolta, 

 Metzner). This parasite has been found by chance 

 during post mortem examinations and during ex- 

 aminations of the stools for other parasites ; in 

 most cases it did not appear to be responsible for 

 any special symptoms, but Railliet and Lucet have T.y | 

 found it in two cases associated with symptoms of 

 chronic diarrhoea. | JX 



Morphology. FlG 360. Coccidiosis in the rabbit. 



If the contents of one of the cysts be ex- 

 amined under the microscope in a drop of 

 water or normal saline solution the parasite can be seen quite distinctly. 

 The Coccidia stain badly, so that if a drop of an aqueous solution of eosin 

 be added to the above preparation the parasites stand out conspicuously 

 as unstained objects on a pink background. 



For studying the structure of Coccidia, Pianese fixes small pieces of the liver 

 for 36 hours in a mixture consisting of : 



10 per cent, aqueous solution of cobalt chloride, - 20 c.c. 



2 per cent, aqueous solution of chromic acid, 5 ,, 



Formic acid, ..... 1 drop. 



Bertarelli advises fixing in a saturated aqueous solution of perchloride of mercury, 

 staining for 24-48 hours in a dilute solution of Grenacher's haematoxylin (1 c.c. 

 hsematoxylin in 200 c.c. of water) and differentiating in acetic-alcohol. 



Borrel gives a method for fixing and staining which is particularly useful for 

 studying sporozoa in sections : 



Place very small pieces of the tissue in the following mixture for 24 hours in the 

 ice chest : 



Osmic acid, 2 grams. 



Platinum chloride, - 2 



Chromic acid, - 3 ,, 



Acetic acid, 20 



Distilled water, - - 350 



Wash in a large quantity of water. 

 Embed in paraffin. 



Stain thin sections for 1 hour in the cold in a saturated aqueous solution of Magenta 

 red and differentiate for 510 minutes in the following solution : 



Saturated aqueous solution of picric acid, 1 volume. 



Saturated aqueous solution of indigo -carmine, 2 volumes. 



Wash rapidly. Decolourize in absolute alcohol, then hi clove oil, and leave the 

 section in clove oil for some little time. Mount in balsam. The nuclei will be stained 

 red, the protoplasm blue-green, and haemoglobin yellow or yellowish green. 



Coccidium cuniculi is found in the epithelial cells lining the bile ducts. In 

 these cells the cysts which are oval in shape measure about 4(V long x 20/A 

 broad. They are filled with granular protoplasm which soon retracts from 

 the wall and forms a separate sphere with a centrally placed nucleus : this 



