HATCHING OF STENOPSOCUS CRUCIATUS 



63 



the eyes, and the rupture continues down the back to about 

 the fourth dorsal segment. There is often a pause here, but 

 all the pulsating movements continue ; then suddenly and 

 gently the enveloping membrane slips off the clypeus, down 

 the front, taking the egg-breaker with it ; the mouth-parts 

 are uncovered, and the labrum flaps up and down ; the 

 antennae in their turn are set free and expand ; immediately 

 afterwards the first pair of legs for a moment are thrown out 

 to their fullest extent, then instantl)- retract to kick the 

 amnion skin over the second pair, which push it over the 

 third pair without delay, and all six legs give it a final kick 

 into a little crumpled pel^t in which the chitinised egg- 

 breaker is conspicuous. 

 The freed larva is no ^^.^^^ 

 longer cylindrical, but 

 has assumed a flattened 

 appearance proclaiming 

 its relationship to the 

 Book - Louse, which it 

 now closely resembles. 

 The pulsating move- ' 



ment at the head subsides, and ceases in one and a half 

 or two minutes. Air-bubbles continue to come in at the 

 mouth. As the body is extended to its full length at first, 

 they are clearly seen in a chain reaching to the sixth 

 segment behind the head. Soon the abdomen contracts 

 as in Fig. 5, and they can only be observed through the 

 epicranium. In a short time they are no more to be seen, 

 though not till after the larva has begun to run actively 

 about in search of food. 



M'Lachlan^ states that Psocids moult four times, an advance 

 towards the winged adult form being accomplished at each 

 moult. According to my experience here in Edinburgh, 

 oviposition takes place in July. After depositing a number 

 of eggs in a cluster on the under side of a leaf, the female 

 secures them in a network of silken threads, drawing the 

 cord from her mouth, and stooping her head to peg it down 

 at the turning places, with some organ situated at the side 



1 Efit. Mo. Mag., 1866-7 



