556 PRINCIPLES OF VETERINARY SURGERY 



Fioreiitini it is due to haemorrhages accompanying painful 

 delivery, the calf being more of less compressed in the 

 passages and the extravasated blood undergoes a melanic 

 transformation. The spots thus observed are destined to 

 disappear. But this theory of Fiorentini on the formation 

 of pigment is not based on probability. Indeed melanotic 

 tumors that are not traumatic are found in calves. Besides, 

 if the origin which Fiorentini attributes to it were correct, 

 the melanic infiltration would disappear with age, but it has 

 often been found in adult animals. Moreover, how could 

 the frequency of melanosis in the protected places like the 

 brain and the spinal cord be explained? The formations of 

 melanotic alteration in the calf must be explained otherwise. 



The first theory held by Breschet, et al, acknowledged 

 that melanosis is an alteration of the coloring matter of the 

 blood,— the hjematin, — and there is some reason in expla- 

 nation, as Heurtaux says : "If the hsematin supplies the ele- 

 ments of the pigment it certainly is not the consequence of 

 sanguineous infiltration, and of an alteration resulting from 

 the red corpuscles extravasated among the elements of the 

 tissues. The authors who believe in the hsematin origin of 

 pigment have not claimed that the blood outpoured is di- 

 rectly converted into melanin. They simply meant to say 

 that its materials have been borrowed from the blood, and 

 particularly from the coloring matter." 



The second theory, defended by Lebert, et al, attributes 

 the fabrication of melanin to the cell, and Schultz to the 

 connective tissue cell, without the intervention of the red 

 blood corpuscles. Of these theories the first is unaccept- 

 able and the two others lead to the conclusion that among 

 six weeks' old calves intended for the butcher melanosis is 

 congenital. It may be acquired in older animals and both 

 origins may be found in the same animal. The color of 

 the animal's coat would not, any more than among soli- 



