Following the incubation the marked phenomena are tonic contractions of groups of muscles beginning usually with those near to the seat of the infected wound and extending with varying rapidity to the locomotor muscles generally (limbs, croup, back, loins, neck, tail, abdomen) and those of mastication (jaw) and the eye. The muscles of respiration are only involved at a late date, causing stertorous breathing and it may be asphyxia. Peristalsis is impaired so that there is some costiveness and tardiness in digestion. Urination becomes difficult and infrequent on account of the difficulty of assuming the normal position for the act, and spasm of the sphincter vesicæ and dangerous distension of the bladder may follow. The urine is often albuminous and has a high density and color. Priapism is not infrequent in the male. The predominance of the spasm in special groups of muscles has been the occasion of giving different names to individual cases. _Trismus_ or _lockjaw_ is that condition in which the muscles of the jaws are violently contracted so that the incisors can only be separated slightly or not at all. _Orthrotonos_ is that condition in which the muscles in tonic spasms keep the neck, back and loins rigid, straight and unbending, in one horizontal line. _Opisthotonos_ is when the muscles of the spine are in rigid spasm, so that the back and loins are slightly depressed, the tail elevated and trembling, the neck drawn upward with a concave superior border (“ewed”), the head extended and the nose elevated. _Emprosthotonos_ is caused by spasms of the muscles of the ventral aspect of the body, with arching of the back and tucking up of the abdomen. _Pleurosthotonos_ is when the trunk is spasmodically bent to one side, right or left. Spasms of the muscles of the eyeball, cause sinking and apparent diminution of that organ, with the protrusion of the membrana nictitans over one-third, one-half or even more of its front surface. This is often referred to by owners as “hooks”.