76．A few art collectors Tames Bowdoin III of Boston，William Byrd of Virginia，and the Aliens and Hamiltons ofPhiladelphia introduced European art traditions to those colonists privilegedto visit their galleries，especially aspiring artists．and established in their respective communities the idea of thevalue of art and the need for institutions devoted to its encouragement．

(A few art collectors…introduced European art traditionsto those colonists…and established…the idea…and the need…为句子主干)

几个艺术收藏家，波士顿的詹姆士•鲍德温三世、弗吉尼亚的威廉•白尔德租费城的阿里昂夫妇以及汉密尔顿夫妇将欧洲艺术传统介绍给那些被特许参观他们画廊的殖民者，尤其是有抱负的艺术家们，并在他们各自的社区形成了艺术有价值和需要设立机构以鼓励其发展的观念。

分析：

此长句全为主句，没有从句。整句只能找主干与修饰部分，不能分主从句

主干：artcollectors introduced traditions to those colonists and established in the ideaof the value of art and the need for institutions

修饰成分：

（1）几个人名并列：Tames Bowdoin III of Boston，William Byrd of Virginia，and the Aliens and Hamiltons ofPhiladelphia

（2）非谓语动词后缀修饰名词：privileged to visittheir galleries修饰colonists devotedto its encouragement修饰institutions

（3）插入语，especially aspiring artists．

（4）介词短语修饰谓语动词：in their respectivecommunities 修饰established