THE TRAINED HORSES.After an absence of four or five years, Mr. George Bartholomew is again in Boston, having opened his season at the Grand Opera House last night. His company of trained horses includes some old and favorite members. who have added to their accomplishments since they were hero before, and also many new and clever performers. One of the best of them, a gray horse called Ciesar, hasbecome deaf since bis former appearance in Boston, but this defect has been converted into a superiority, the horse having been taught a sign language, in obedience to which he goes through various acts. The entertainment includes a school session (during which a clever mule puts the clock ahead so as to hasten the recess hour), a picnic enlivened bv jumping, see-sawing, etc., a military drill, and finally a grand battle whichfortunately comes off without serious casualty.The audience was large and enthusiastic,and the whole performance extremely credit-abie to the docility of the actors and the patience and sRill of the manager.