404 THOIMCAL W I IJ) LII'F, IN imiTISH GUIANA 



soft parts and later return ing to less delicate food. During 

 the first day of its life the larva grows only two millimeters. 

 On the second and third days it averages five millimeters 

 each. On the foin'th it goes l)ack to two, grows eight on the 

 fifth and fim'shes with a growth of one millimeter on the sixth 

 and last day of its meal. The spiders are now entirely con- 

 sumed and the grub measures twenty-six millimeters in 

 length. 



Without ])ausing for a moment to rest, the full-grown 

 larva now sets about to lay the foundations of its elaborate 

 cocoon. The insect is awkwardlj^ placed at the outset, living 

 as it does in a cell whose perpendicular walls are several 

 times its own length, but fortunately at this period of its 

 life it is endowed with an unusually tacky skin. This sticki- 

 ness serves a special purpose, enabling the grub to remain 

 safely in the top or center of its cell without the slightest 

 danger of tumbling down to the mortar i)lug separating it 

 from the cell below. 



From its lofty position and in total darkness, the grub 

 first throws out several bands of silk, fastening them in vari- 

 ous places about the reed walls. It makes no choice of its 

 own, but simply fastens each successive thread to the first 

 point of contact. Some of the strands pass to points above 

 the spinner, some below and still others across the middle 

 of its body to the wall beyond. At length the grub finds 

 itself more or less enclosed in a delicate silken net through 

 the strands of which it may still poke its head. 



Thirty or forty new threads are now extended from the 

 top of the growing cocoon. They emerge from various points 

 in a circle, and are fastened to the cell wall above. The larva 

 noM^ returns to its original network, within which it spins a 

 firm torpedo-shaped covering, slightly wider tlian its own 

 body, nineteen millimeters in length and open at the upper 

 end. Through this opening a ring of silk is spun, two milli- 

 meters in lieight, with a scalloped edge, the point of each scal- 

 lop forming one of the thirty or more strands extending 



