196 



able symptoms during life. They are foimd in horses at all ages, and 

 are of slow develoi^meut. The}" are found in one or both of the lateral 

 ventricles, enveloped in the folds of the choroid plexus. 



Melanotic tumors have been found in the brain and meninges in the 

 form of small, black nodules, in gray horses, and in one instance are 

 believed to have induced the condition known as string-halt. 



Fibrous tumors may develop within or from the meningeal structures 

 of the brain. 



GHomatous tumor is a variety of sarcoma very rarely found in the 

 structure of the cerebellum. 



Treatment for tumors of the brain is be^'oud our ambition in the pres- 

 ent age. 



SPASMS — CRAMPS. 



Causes. — Spasm is a marked symptom in many diseases of the brain 

 and of the spinal cord. Spasms may result from irritation of the motor 

 nerves as conductors, or may result from irritation of any part of the 

 sympathetic nervous system, and they usually indicate an excessive 

 action of the reflex-motor centers. Spasms may be induced by various 

 medicinal agents given in poisonous doses, or by eftete materials in the 

 circulation, such as nux vomica or its alkaloid strychnia, lead prepara- 

 tions, or an excess of the urea products in the circulation, etc. Spasms 

 may be divided into two classes: tonic spasm, when the cramp is con- 

 tinuous or results in persistent rigidity, as in tetanus; clonic spasm, 

 when the cramping is of short duration, or is alternated with relaxa- 

 tions. Cramps may be distinguished from choleraic movements by the 

 extreme pain or suflering which they induce. Spasms may afiect invol- 

 untary as well as the voluntary muscles, the muscles of the glottis, 

 intestines, and even the heart. They are always sudden in their devel- 

 opment. 



SPASM OF THE GLOTTIS. 



This is manifested by a strangling respiration ; a wheezing noise is 

 produced in the act of inspiration ; extreme anxiety and suflering for 

 want of air. The head is extended, the body j)rotusely perspiring; 

 pulse very rapid; soon great exhaustion becomes manifest; the mucous 

 membranes become turgid and very dark-colored, and the animal thus 

 may suflbcate in a short time. 



SPASMS OF THE INTESTINES. 



(See "Grampcolic") 



SPASMS OF THE NECK OF THE BLADDER. 



This may be due to spinal irritation, or a reflex from intestinal irrita- 

 tion, and is manifested by frequent but iueflectual attempts to urinate. 



