“Deep in the forest a call was sounding, and as often as he heard this call, mysteriously thrilling and luring, he felt compelled to turn his back upon the fire and the beaten earth around it, and to plunge into the forest, and on and on, he knew not where or why; nor did he wonder where or why, the call sounding imperiously, deep in the forest.” ― Jack London, The Call of the Wild.
I think I understand that a comma gets used to point to the location of a clause boundary and that 'and as often as he heard this call' gets separated from the previous clause because it contains the conjunction 'and' (?)
Can I confirm that 'mysteriously thrilling and luring' is an adjectival phrase while 'he felt compelled to turn his back upon the fire and the beaten earth around it' and 'he knew not where or why' are independentant clauses?