"Since the spiders would not bite, I carefully ground up the fresh animals in physiological salt solution, preparing an extract which must have contained, in solution, all of the poisonous substance of their bodies. While in the case of _Latrodectus_, as we shall see, less than one specimen sufficed to yield an active extract, I have injected the filtered extract of six fresh Russian tarantulas, of which each one was much heavier than an average _Latrodectus_, subcutaneously and into the jugular vein of various cats without the animals dying or showing any special symptoms. On the basis of my experiments I can therefore only say that the quantity of the poison soluble in physiological salt solution, even when the spiders are perfectly fresh and well nourished, is very insignificant. That the poison of the Russian tarantula is not soluble in physiological salt solution, is exceedingly improbable. Moreover, I have prepared alcoholic extracts and was unable to find them active. Since the Russian spider exceeds the Italian in size and in intensity of the bite, it seems very improbable to me that the pharmacological test of the Italian tarantula would yield essentially other results than those from the Russian species." To the AVICULAROIDEA belong the largest and most formidable appearing of the spiders and it is not strange that in the New World they have fallen heir to the bad reputation, as well as to the name of the tarantula of Europe. In this country they occur only in the South or in the far West, but occasionally living specimens are brought to our northern ports in shipments of bananas and other tropical produce, and are the source of much alarm. It should be mentioned, however, that the large spider most frequently found under such circumstances is not a tarantula at all, but one of the Heteropodidæ, or giant crab-spiders, (fig. 8). [Illustration: 8. The giant crab-spider or banana spider (Heteropoda venatoria). Natural size. After Comstock.] In spite of their prominence and the fear which they arouse there are few accurate data regarding these American tarantulas. It has often been shown experimentally that they can kill small birds and mammals, though it is doubtful if these form the normal prey of any of the species, as has been claimed. There is no question but that the mere mechanical injury which they may inflict, and the consequent chances of secondary infection, justify, in part, their bad reputation. In addition to the injury from their bite, it is claimed that the body hairs of several of the South American species are readily detached and are urticating.