BLOOD. 343 



other. This is a point of no slight importance, for it indicates 

 the necessity that exists for the determination of the consti- 

 tution of the healthy blood in every individual class of animals 

 before we can venture to draw any conclusions regarding the 

 blood in a morbid state. 



The mean amount of fibrin in one class of animals is as low 

 as 2-1, while in another it rises to 4-G per mille, one being 

 considerably lower, the other much higher, than in man. 



The largest amount of fibrin observed by Andral, Gavarret, 

 and Delafond, was in swine, the maximum being 5-0, and the 

 minimum 4*1; the animals were from 2 to 6 months old, and 

 had been restricted for some time to a diet of horse-flesh. In 

 a two-year old sow that had been fed purely on vegetables, and 

 was very fat, the fibrin did not exceed 4-0. The blood of 

 horses ranks next to that of swine in the amount of fibrin, the 

 observed mean being 4-0, the maximum 5-0, and the minimum 

 3-0. Next to horses come neat cattle, the mean amount of 

 fibrin in their blood being 3-7, the maximum 4-4, and the mi- 

 nimum 3-0. The blood of the bull does not contain a larger 

 amount of fibrin than the blood of the cow or the ox. The 

 blood of the Merino sheep contains on an average the same 

 amount of fibrin as human blood, i namely, 3-0; in the blood of 

 English sheep a smaller amount of fibrin was obtained. The 

 smallest quantity of fibrin was found in the blood of dogs, the 

 mean being only 2-1, the maximum 3*5, and the minimum 1-6. 

 The minimum occurred in dogs feeding on an exclusive animal 

 diet. From these observations it is evident that each class of 

 animals contains in its blood its own standard amount of fibrin. 

 The blood-corpuscles are found to occm', for the most part, in 

 an inverse ratio to the fibrin ; that is to say, in blood that con- 

 tains a large amount of fibrin, the amount of the corpuscles is 

 small, and vice versa. It was shown by special experiments 

 that there is no connexion between the strength of the animal 

 and the amount of fibrin. The amount of fibrin varies consi- 

 derably before delivery and immediately afterwards, during the 

 milk-fever J in the former case it is at its minimum, in the 

 latter it attains its maximum. 



The amount of solid residue of the serum varies between 

 75-5 and 92-4. The former number occui's in the blood of the 



' Andral aud Gavarret always refer to Lecaiiii's standard. 



