II. PREVENTING THE GROWTH OF HORNS 



BY H. H. LAMSON 



Many of the disagreeable features of dehorning may be 

 avoided by preventing the horns of calves from developing. 



The horns of cattle consist of two parts of different origin ; 

 the outer horny shell is a growth derived from the skin ; the 

 inner part or pith consists of bone and is an outgrowth of the 

 skull. See Fig. 3. 



At the birth of the calf each of these parts is undeveloped 

 and only exists as a possibility but they at once begin to grow, 

 and in a short time the young horn can be felt as a slight eleva- 

 tion or button. 



Bones are covered with a tough, fibrous membrane known as 

 the periosteum, from the inner surface of which new bone is 

 continually being formed upon the surface of the old. It is in 

 this way that growth in size is produced, and it is thus that the 

 bony part of the horn grows. 



The horny tissue develops from the skin just as do hoofs and 

 claws in the lower animals and nails in human beings. There 

 is a zone in the skin about the base of the horn known as the ma- 

 trix, from which new horn-cells are constantly being formed, the 

 older parts being pushed on. If we destroy the periosteum from 

 which the bony part of the horn is formed and the matrix from 

 which the horny part is formed we prevent the further develop- 

 ment of the horn. In removing horns which are already more or 

 less developed, as in dehorning mature animals, the cut must be 

 made deep enough to include the matrix or the stump of the 

 horn will continue to grow. It may not be out of place here to 

 remark that there is no danger of cutting into the brain-cavity, 

 as at this point it lies very deeply. The openings frequently 



