The first part of this paper tries to show that the ＂Wu dialect＂ (吳語 Wuyu) of the Southern dynasties (420-589 A.D.) was the source of Modern Min dialects, a thesis first proposed by Ting Pang-Hsin (1988) and Jerry Norman (1983). Two types of new evidence are presented. First, in the 孔雀王咒經 (Mahamāyūrī) (Taisho Tripitika, No.984) translated into Chinese by the Cambodian monk Sanghabhara (460-524 A.D.), the character 寒 han 'cold (of weather)' Middle Chinese yan with the subscript Wuyin 吳音 ＂Wu pronunciation＂ transcribes the first syllable of Sanskrit Gandhāra. 寒_(吳音)那里 = Sanskrit Gandhāra. This means the initial of 寒 han in the ＂Wu dialect＂ was g-. The second type of evidence consists of the Wu dialects of the Chuqu (處衢) region of Southern Zhejiang, especially the Qingyuan 慶元 dialect, deep in the hills of southwest Zhejiang. Below I present three comparative tables illustrating the lexical and phonological similarities between Qingyuan and Min dialects. (2) Middle Chinese 匣母 Xia initial (X-) words with *g- initial in Min and Southern Wu dialects: The form abridges (3) Old Chinese Ge category 3rd division (歌部三等) words with *-jai final in Min and Southern Wu dialects: The form abridges (4) Ancient dialect words preserved in Min dialects were also preserved in Southern Wu dialects: The form abridges (1) and (2) show that all the Xia initial 匣母 words with unrounded vowels had Old Chinese *g- initial in the Wu dialect of Southern dynasties, and in its daughter dialects-the Min dialects and the Wu dialects of Southern Zhejiang. (3) shows that Old Chinese Ge category 3rd division words such as 蟻 yi 'ant', 徛 ji 'to stand', and □xi 'ladle' had *-jai final in Min and Southern Wu dialects, and that, as Ting Pang-Hsin (1983) has shown, the *-jai final of these words preserves the *-jar final of the Western Han period. (4) shows that ancient dialect words such as 渹 Middle Chinese ts'j!n 'cold', 儂 MC nuong 'man, human being', 骹 MC khau 'leg, foot', 薸 MC bjau 'duckweed, algae', □MC xjie 'a ladle, a scoop', and 䘼 MC ^ʔjw□n 'a sleeve', preserved in Min dialects, are also preserved in Southern Wu dialects such as Qingyuan 慶元. (1), (2), (3) and (4) together show that the ＂Min dialect＂ of Southern dynasties is ancestral to both the Min dialects and the Southern Min dialects, and that the time of its separation from the main stream of the Chinese language can be firmly dated towards the end of the Western Han period (206 B.C. - 8 A.D.). The second part of this paper presents an exegesis of Yan Zhitui's (531–597? A.D.) dictum in the Family Instruction of the Yan Clan, ＂The South is tainted by the linguistic features of Wu and Yue, and the North is intermixed with the barbaric tongues of Yi and Lu＂ 南染吳越, 北雜夷虜. The interpretation of the first clause draws upon the same type of evidence used in the first part of this paper. The interpretation of the second clause rests upon the fact that the Chinese word for older brother, 哥 ge, is a loan words form Xianbei 鮮卑 (an Altaic language) *aqa 'father, older brother' and 阿干 a-kan 'older brother'.