310 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



which LinneBiis thence called Acarus dysenteric" Among 

 the most singular of all mites are those which live under the 

 skin and on the superficial veins of certain birds. They are, 

 as would naturally be supposed, quite low in their organiza- 

 tion. One species lives in the air-cells under the skin of the 

 solan goose, another lives in the bronchial tubes of the com- 

 mon swift of Europe, and another in the air-tubes and lungs 

 of the butcher-bird, another {Ilypoderas Uneatus) in the fat- 

 ty masses which lie in the arm-pit on the outer margin of the 

 pectoral muscle. Ilypoderas eolumbee is a small maggot-like 

 animal, distinctly visible to the naked eye, and lives in the 

 connective tissue of the skin, on the large veins near the 

 heart, and on the surface of the pericardium of the pigeon. 

 This and allied forms are figured by Mr. Murray. 



Dr. Forel has described the habits of a poisonous spider 

 (Chiracanthium nutrix of Walkenaer) which lives in the 

 hedges of Switzerland in the autumn. The female spins a 

 very fine and dense silken cocoon as large as a hen's egg, but 

 more or less spherical. It is in this hermetically closed case 

 that the spider places her packet of eggs. If a cut be made 

 in the cocoon, the spider shows her head, opens her large 

 mandibles, and death awaits those that suffer themselves to 

 be bitten. If a living fly be ottered to it, it falls dead at the 

 first bite. When the spider has bitten once or twice, its poi- 

 son, contained in its hollow mandibles, becomes diminished 

 in quantity and less deathly. When it bites a rather large 

 insect, the latter becomes stupefied a few minutes and then 

 entirely recovers. Several years ago Dr. Forel was bitten in 

 the finger by a female. lie felt a violent pain in the hand 

 and arm as high up as the elbow. For at least a minute af- 

 ter he felt sick, a cold sweat passed over him, and a friend, 

 who was with him, held him up by the arm and led him into 

 the house. There was no swelling. The general malaise 

 and pain in the arm soon dissipated, but the bitten place re- 

 mained painful for several days. It is a peculiarity of this 

 poison that its effect is sudden and deadly, and of short dura- 

 tion, both in man and in insects. The male wanders near the 

 nest of the female. It is smaller, slenderer, and its jaws are 

 feebler. It is also poisonous, though less so than the female. 

 'I have been twice bitten by it. The pain is severe, but 

 local and transitory. One day I placed a female in the web 





