96 GEORGO ORIHAY SHINJI 



observation on several coccids shows, it should be repeated, 

 that the mouth parts of these coccids (Homoptera), are formed 

 essentially in the same manner as in Corixa, a Heteropteran. 



The side view of the last embryonic stage is shown in figure 56. 

 In each of the thoracic limbs, the first joint or coxa becomes 

 conical. Contraction has also considerably reduced the length 

 of the trochanter. The embryo is now shortened to the length 

 of the egg-shell and is much flattened. The alimentary canal is 

 already completed, and the ventral nerve cord is contracted a 

 great deal. A great change has also occurred in the oral append- 

 ages. The tips of the mandibles and first maxillae become 

 elongated, extending beyond the rest of the oral appendages to 

 form slender lancelet-like processes, while the rest of the oral 

 appendages unite and form a sort of case at the base of the 

 piercing processes. A careful examination of a mounted speci- 

 men of this or a slightly older embryo shows that the antennae 

 are covered with a long slender hair-like process at each joint. 

 There are also tail filaments, three on either side of the posterior 

 extremity of the tenth abdominal segment. The embryo is now 

 ready to hatch. 



In the case of the cottony cushion scale, I have observed the 

 process of hatching. The first indication of this process is the 

 appearance of a transverse slit, usually around the mesothorax, 

 often, however, on the metathorax. Through the rent thus formed, 

 the antennae, which have been folded against the ventral surface 

 of the body, gradually stretch out. By the force thus exerted 

 by the antennae the cephalic portion of the insect becomes first 

 lifted and then carried forward from the egg shell by the stretch- 

 ing antennae, meanwhile the embryo juggles its abdominal 

 portion by exertion on the part of the long caudal filaments. 

 Then the femur of the first thoracic leg and a part of the first 

 tibia appear. With the next exertion the most of the body and 

 legs become free from the egg shell. The rest of the process is 

 the kicking off, so to speak, of the shell from the filaments by 

 means of legs, and the hatching is completed. 



The embryo, eight hours after hatching, is represented by 

 jBgures 57 and 75, of Pseudococcus and Icerya, respectively. 



