TEGENERIA MEDICINALIS. 



inflamed and swelling. The larger the spider, the warmer 

 the climate or season of the year, and the more susceptible 

 the wounded individual, so much worse will the effects be; 

 and it is therefore no wonder that people who would have a 

 fester from a simple prick with a needle should feel more 

 violent effects from the bite of a spider. Thus the bite of 

 the Tarantula in Southern Italy, according to late observa- 

 tions, is said not to be nearly so dangerous as it was consid- 

 ered formerly, and the disease attributed to the bite of the 

 Tarantula is said to be more the consequence of the climate 

 and manner of life of the people. It is, however, an indis- 

 putable fact, that spiders defend themselves when they are 

 persecuted and captured, bite with their choice, and drop into 

 the wound a more or less poisonous juice, although the con- 

 sequences are of little importance and the wound is very sel- 

 dom dangerous. 



There is a small Tick, so commonly called the Red Spider, 

 Acarus telarius, that it may be described here. It is scarcely 

 visible to the naked eye, and does considerable injury to vari- 

 ous plants in warm, dry summers. It is also called the Plant 

 Mite. Like most of the Arachnidce, it has eight legs, its 

 color changes from yellowish to brown and reddish, and on 

 each side of the back is a blackish spot. In the open air it 

 usually attacks kidney beans. Among trees the young limes 

 principally suffer, and the mites are found in thousands on 

 the under side of the leaves. These leaves assume a dirty 

 yellow or brownish appearance, and in the middle of summer 

 the trees acquire an autumnal hue. In hot-houses the red 

 spider feeds during the whole year, and is a great pest to 

 nurserymen and gardeners. It spins a sort of web over the 

 leaves, particularly on the under surface, and sucks the juice 

 of the plants with its rostrum, which completely enfeebles 

 and defoliates them. Sprinkling the plants frequently with 

 cold water has been found efficient as a means of destroying 

 these insects ; fumigating the hot-house repeatedly with strong 

 tobacco smoke also injures them in some degree. They are 

 most abundant when the plants are kept too warm in sum- 

 mer, and as most hot-house plants thrive well when placed in 

 the open air in July and August, placing them out will almost 

 entirely free them from these insects. When hot-house plants 

 are placed in the open air, the precaution must be taken of 

 sinking the pots in a warm dung or tan bed, to keep the roots 



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