History of Germany, Opening the book

Here is one of the books I will be working from. This is only the beginning and I hope to bring in other resources and writings as well. If anyone has suggestions for other reading materials I will gladly look into them! Post links in comments below. 

History of Germany by Bayard Taylor  
Here is a link to find more information on the book and author or if you're as eager as me you can purchase it as well. 

The book begins in 330 B.C. and opens stating that "the German's form one of the most important branches of the Indo-Germanic or Aryan race-- a division of the human family which also includes the Hindoos, Persians, Greeks, Romans, Celts, and Slavonic tribes." It goes on to say that the relationship of all these groups, that have since become separated, has been established by evidence of common tradition, language, and physiological structure. Their original home seems to have been up in the mountains somewhere in Central Asia. 

I have not studied much about the Aryan race so this will be a learning experience for me. I also had no idea the Aryan race included Hindoos, Persians, Greeks, Romans, Celts, and Slavonic tribes. 

Taylor goes on to say, "Arya meaning the high or the excellent indicates their superiority over neighboring races long before the beginning of history." 

So my first question would be why Hindoo and not Hindu I found an interesting blog, Religion and American History, that explained the difference between the two. A quick summary of this post being that we used Hindoo when we were less educated on the culture and it was transitioned in America into Hindu by a monk named Swami Vivekananda. 

For today that's what I have learned. I had to check and verify that