792 THE POPULAR SCIENCE MONTHLY. 



to one which is running rapidly along the road or trying to hide 

 itself in the grass. It is carrying a pure white, round shell — the 

 sack containing the eggs — in making which it has expended all 

 the silk it had (Fig. 4). A mother of incomparable vigilance, 

 homeless, its eggs laid and well protected in the silky walls of the 

 shell, it does not abandon the cradle of its offspring for an instant. 

 If we succeed in seizing one of the animals during its journey and 

 take away its cocoon, the spider, usually so timid, instead of run- 

 ning away, makes a show of fight against the aggressor. If the 

 cocoon is on the ground, it makes most earnest efforts to take it up 

 and run away as quickly as possible. As soon as the young are 

 hatched they attach themselves to the body of their mother, and 

 she carries them till they are strong enough to hunt a prey, crafty 

 enough to deceive an enemy, and ungrateful enough to cease to 

 recognize a mother whose care has become of no use to them. 

 Large lycosas adorned with lively colors inhabit southern Europe, 

 Africa, and some parts of Asia. They are wanderers like their 

 congeners of cold and temperate countries, and have the advan- 

 tage over them of a longer existence and of having fixed retreats. 

 They dig a cell in the ground, tapestry its walls, and weave a bar- 

 ricade of crossed threads across the entrance. Among them is 

 the tarantula, concerning the effect of whose bite many marvel- 

 ous but fictitious stories are told. 



The smaller rivers of Europe are inhabited by an aquatic 

 spider, the Argyronetus aquaticus, the first observation of which 

 was a considerable surprise to the Pfere de Lignac, who discovered 

 it and first described it. It was in 1747, and he was bathing in a 

 river near Mans, when, he relates, " I was surprised by a wonder- 

 ful sight : bubbles of air, bright as polished silver, appeared to 

 swim around me and follow me. Their free movements, which 

 were not determined by the motion of the water or by the levity 

 of the air, declared that they were animated. My surprise shortly 

 became astonishment when I perceived that they were large 

 spiders whose bodies were enveloped in air." Two years after- 

 ward, Lignac obtained several specimens of the argyronetus, and 

 made a closer study of them. While their nearly constant abode 

 is the water, they are, like most other spiders, air-breathers ; con- 

 sequently they need some special provision for providing them- 

 selves with air while living under the water, and for this purpose 

 they possess the art of constructing a kind of diving-bell. It is 

 an interesting sight to witness one of them making his air-cell. 

 Clinging to the lower side of a few leaves, and securing them in 

 position by spinning a few threads, the spider rises to the level of 

 the water, with its belly uppermost, and, doubling up its hind-legs, 

 retains a stratum of air among the hairs with which its body is 

 covered. Then it . plunges into the water and appears as in the 



