MOULTING HABITS OF SPIDERS. 103 



side and the door fell back, keeping an attachment to the wall.^ This 

 is especially the case with Lycosa tigrina. 



Wagner confirms this observation in the case of the European taren- 

 tula, which closes its burrow with a sort of pent house above the door, 

 and suspending itself to the sides thereof, head downward, passes its moult. 

 In captivity these prei^arations change in their details, but their aim 

 remains the same, and is always attemjDted in one way or another. ^ 



It seems probable, as suggested by Wagner, that the nature and extent 

 of these precautions depend upon the facility with which the moult is 

 accomplished ; the greater the facility the less the precaution. 

 Facility -pov example, young spiders appear to experience little or no 

 in ou - ^igjg^ii^y JQ shedding their coats, which they do in a few min- 

 utes — young Orbweavers in from three to ten minutes, young 

 Trochosas in two minutes. As the spiders advance in age the succeeding 

 moults are passed with increasing difficulty, the last moult being often 

 the hardest to achieve. Now, young spiders make no preparations and 

 take no precautions in moulting, and drop their skins wherever they 

 chance to be, a carelessness which disappears with the approach 

 ^™^'''^ of adult life. Thus Wagner records that the young of Trochosa 

 <a . "^ singoriensis make no protective defenses during the early period 

 of life, when they moult easily ; but as the act is made more 

 difficult and protracted by advancing age, they cover their burrows when 

 they feel the moulting period coming on. 



The Thomisoids quite generally shed their skins easily and rapidly, 

 and, accordingly, they do it openly, only spinning a supporting thread 

 over the petals of a flower or the surface of a leaf. Even in the case of 

 some young spiders one may see evidence of the same sensitiveness to 

 danger, for if the young of Attus terrebratus, who are in the habit of 

 moulting en masse within the maternal cocoon, be removed after the 

 second moult and put in a suitable place, every one will spin a little cell 

 within which the third moult is separately made. This quick perception 

 of the change of condition and ready adaptation thereto is justly noted 

 by Wagner, who relates it as a fine example of instinctive wisdom. 



My tarantula " Leidy," distinguished by having reached the greatest age 

 of any spider known to science, finally died in the act of moulting when 

 more than seven years old. Its death is another example of a fact which 

 I had previously observed, that the act of moulting is frequently attended 

 by dangers of one kind or another to spiders. It is common to find 



' My Garden Pets, page 82. 



2 One needs to distinguish between the word tarantula, which is the popular name for 

 the huge Mygale of our southwestern States, and the genus Tarentula of the Lycosids. The 

 Turret spider (L. arenicola) and my Tarentula (Lycosa) tigrina are closely related in habits 

 and structure to the fiimous "tarentula" of Italy, and the well known Tarentula (Lycosa) 

 Narbonensis. 



