BY R. .1. TILI.YAKD. 805 



iiig vigorously at its victim. It may take some hours before the 

 latter is completely emptied of its juices. By this time, the 

 Psychopsis larva will have swollen out to a very great extent, 

 and will frequently be quite torpid, like a snake. After such a 

 meal, no food should again be offered for two or three weeks. 

 Larv?e that are overfed usually die from the effects of it; so that 

 it is necessary to keep a strict watch on the feeding, and only to 

 offer food to those that are really in need of it. 



The Cocoon. (Plate Ixxix., fic^ji). 



When the larva is full fed, it remains torpid for a considerable 

 period, usually two or three weeks. It then sets about con- 

 structing its cocoon. First of all, a number of loose and irregular 

 threads are spun from the anus, making an irregular mesh work, 

 the size and appearance of which depends entirely upon the place 

 selected for the cocoon. Under natural conditions, the cocoon 

 is spun in a crevice of the bark, which is usually barely wide 

 enough to contain it. In such a case, the preliminary meshwork 

 is reduced to a minimum, and only consists of a slight scaffolding 

 or anchorage for the cocoon. But, in such an artificial condition 

 as in a glass-tube, the larva may expend a considerable amount 

 of skill upon this meshwork, before it is satisfied that conditions 

 are satisfactory for the actual building of the cocoon. 



Having selected the exact position for the cocoon, the larva 

 next spins a small platform within the meshwork already men- 

 tioned. Upon this it lies, back downwards, while it weaves 

 around itself, with mar\ellous dexterity, the beautiful spherical 

 cocoon. The outer sheath of the cocoon is mostly composed of 

 fairly loose and irregular threads; as these are spun in larger 

 and larger number, the spherical shape of the cocoon begins to 

 take shape. Within tliis loose outer covering, the threads are 

 spun with wonderful accuracy and closeness, so that the larva is 

 finally enclosed in a dense white or cream-coloured ball of silk, 

 which, when cleared of its outer and looser threads, closely re- 

 sembles a pearl. As the spinning proceeds, the larva shrinks 

 more and more in size, and becomes doubled right over upon 

 itself. When the cocoon is finished, it becomes almost impossible 



