[1911] 



Hatching of the Walking Stick. 



189 



The method employed during the process of emerging from 

 the egg is almost identical with that which we (10) have des- 

 cribed of a walking-stick withdrawing itself from its old skin 

 during the process of ecdysis. A specimen examined under a 

 binocular microscope during the process of emergence from the 

 egg, will be seen to undergo a series of peristaltic-like movements 

 of the segments of the body; these movements pass from the 

 posterior end of the abdomen towards the head. With each 

 series of these movements, the body is drawn out of the egg- 

 shell a short distance, the legs also assisting somewhat in this 

 process of extraction. At each pull of the legs in their attempted 

 withdrawal from the egg-capsule, the strength of the pull is 

 such, that the coxa of each leg presses against the body, causing 

 in that region a temporary indentation. When the peristaltic- 

 like movements reach the head, the walking-stick often raises 

 the head vigorously upward in an attempt to withdraw the 

 antennae. 



The first part of the walking-stick to leave the egg is the 

 dorsal surface of the prothorax (Fig. 3, p) ; then comes the head 

 (Fig. 3, h), followed by the rest of the thorax. The antennae 

 are freed next, and these may come forth either simultaneously 

 or one soon followed by the other. The following order was 

 often observed in the withdrawal of the legs: one middle leg 

 was followed by the other; then the front legs were pulled out 

 of the egg at the same time,' and finally the hind legs. The 

 abdomen does not leave the egg at any definite time in relation 

 to the withdrawal of the other parts, but it may emerge after the 

 antennae or, in other specimens, after the middle or front legs. 

 The extrication of the antennae, legs and abdomen, however, 

 does not always take place in the order just given, as is shown 

 in the following table: 



Table I. 



Order of Withdrawal of the Antennae, Legs and Abdomen from the Eggs of Six 

 Diapheromera femorata. 



f antenna 

 lantenna 

 front leg 

 middle leg 

 middle leg 

 front leg 

 abdomen 

 /hind leg 

 \hind leg 



antenna 

 antenna 

 middle leg 

 abdomen 

 middle leg 

 front leg 

 front leg 

 (hind leg 

 \hind leg 



antenna 

 antenna 

 abdomen 

 middle leg 

 middle leg 

 front leg 

 front leg 

 hind leg 

 hind leg 



middle leg 

 antenna 

 middle leg 

 antenna 

 abdomen 

 front leg 

 front leg 

 fhind leg 

 \bind leg 



abdomen 

 /antenna 

 lantenna 



middle leg 



front leg 



front leg 

 /middle leg 

 \hind leg 



hind leg 



thrown off. 



abdomen 

 antenna 

 antenna 

 middle leg 

 middle leg 

 front leg 

 front leg 

 hind leg 

 hind leg 



Braces indicate that the two included appendages were extricated simultaneously. 



