Mrs. Manners neatly covers a major base left untended by Birmingham (but not by more scholarly others) -- the effect on German and Sephardic American Jews of the explosive entry and adjustments of two million East European Jews who came to this country in the late 19th century. The author, with the humorous, caustic accuracy of Yiddish, calls this reponse a symptom of the tsitterdik syndrome -- a wary nervousness brought on by the contemplation of the ""unenlightened, indigent, badly dressed and Medieval"" flood in successive waves of immigration. Led by substantial and responsible city lights like Jacob Schiff and Louis Marshall, the ""uptown"" cousins moved to the aid of the newcomers. They coaxed, lectured, organized, generously offered leadership and financial help. But sometimes their efforts were met with resentment, particularly that of the Orthodox religious, the adventurous and the free spirits of the downtown enclaves of ""Odessa East."" Mrs. Manners highlights her version of conflicting currents with amusing and revealing happenings: the infamous unity banquet of congregational leaders at which Little Neck clams were served but not eaten before the outraged exodus; the violent rights protest of Ward's Island immigrants set off by a hurled bowl of tzimes; an admonitory broadside from ""Techter fun der Amerikanishe Revolution"" when the Gentiles tried a hand with the wild bunch; the brief tumultuous term of the ""kehillah"" to fight Jewish crime. There are discussions of efforts to smash the ""Jewish stereotype"" with agricultural communes and schooling and programs of Jewish agencies to disperse the immigrants throughout the country. Mrs. Manners profiles some successful descendants of the dispersees and a few eminent personalities from the years of healthy turmoil -- poet Emma Lazarus to anarchist Emma Goldman; Schiff, Wise, Marshall to Abraham Cahan. Poor Cousins deserves a place in the front parlor along with Our Crowd and The Grandees.