LARVAL SACRIFICE 35 



very large insect, or six small ones, and while there is variation 

 in the number of victims, the total bulk and food value of each cell's 

 contents remain the same. 



Two days after the egg is deposited and the cell sealed up \vith 

 clay, the young roach-killer hatches. It is but a tiny grub of thirteen 

 segments, two millimeters in length, rather transparent and concerned 

 only with its mouth and digestive tract. For two days it gorges, 

 selecting only the tenderest, juiciest parts of its victims, leaving the 

 legs and other less nutritious parts untouched. On the fifth day of 

 its existence, it returns to these left-overs, going over and over them 

 until all nourishment is gone. 



One hears the glutton plainly at its feast. Sip-sip-sip, comes 

 the rhythmic sound. Its entire body throbs in unison as the greedy 

 creature dives deeper and deeper into the grab-bag of the roach's 

 anatomy. In five days the feast is over. The wings, egg cases, shells 

 of the heads and thorax, together with the hard limb skeletons of the 

 roaches are left uneaten in the end. They lie about the cell in fine 

 disorder as lasting evidence of the grub's revelry. 



Immediately upon finishing the repast, the larva constructs a net- 

 work of silken threads, just enough to prevent its rolling about. 

 Within this cradle, an inner cocoon is formed, composed of threads 

 much more densely spun, and finally coated within, with a reddish 

 brown fluid that hardens in contact with the air, into a brittle skin. 

 The process of spinning and coating requires eighteen hours for com- 

 pletion, after which the larva excretes the waste from its five-day 

 gorge in a single mass at one end of the cocoon. 



Spinning over, there comes a ten-day pause in the creature's activ- 

 ity, during which time we shall witness the Larval Sacrifice. This 

 process, known as pupation, is in many respects the strangest and 

 most wonderful of all physiological transformations that take place 

 in the insect world. We will see the grub, which in reality is but 



