Tramping Back to Georgia.Atlanta, March 6.--A (special to the Constitution from San ^Anatonio, Tex., says^that twenty-five negroes passed through there to-day walking baei to their old homes in Georgia and Alabama. These negroes were members of a large party of emigrants who left Georgia and Alabama a few weeks ago for Mexico. They were under the leadership of Pegleg Williams, a well known emigrant agent.The negroes say that all the others will leave as soon as they can. They became alarmed at the peonage system oi Mexico and feared that they would be enslaved if they remained.