I just started so not much of a review. But I will paste in an excerpt...
From Chapter 1, "The Black-Bellied Tarantula"
I had seen enough. The quick insect-killer had taught me her trade as had the paralyzer before her: she had shown me that she is thouroughly versed in the art of the butcher of the Pampas. The Tarantula is an accomplished desnucador (Argentine Butcher). It remained to me to confirm the open-air experiment with experiments in the privacy of my study. I therefore got together a menagerie of these poisonous Spiders, so as to judge of the virulence of their venom and its effect according to the part of the body injured by the fangs. A dozen bottles and test-tubes received the prisoners, whom I captured by the methods known to the reader. To one inclined to scream at the sight of a Spider, my study, filled with odious Lycosae, would have presented a very uncanny appearance.
This book has been amazing so far. It reads like "The Lost World".