colletion 解释“收藏品”确实是可数名词,有复数形式.如：
My colletions grew as time went on.
但是 colletion 的单复数是指收藏品的种类,而不是一件件物品的数目（既然是收集的东西,那肯定是复数的）.上述例句中的 colletions 是指各种不同的收藏品（如邮票、书籍、古董）.对于单一种类的物品,收藏起来便是a colletion.如：
Her new book is a colletion of short stories.
a stamp colletion
这样,也就不难理解 a magnificent art colletion 了,因而 most of his magnificent art colletion 也就顺理成章了.