Nos. 455-45<3.] HEAD OF BL ATT A. 



away the antennae and the procephalon, it may 

 sternites of the mandibular and ist maxillar 

 fused, and torm a 

 well marked area ix : 

 ing- between their i\- ; 

 spective apj;enda<;es 

 (Fig. 12, hyp.). We 

 shall refer to this 7mi. 

 again, in the discus- 

 sion of the develop- ^ 

 ment of the sclerites. 



The procephalon is 

 much enlarged and j.^,. 

 at its proximal end is of six 

 wedged in between „mov 

 the cei>halic lobes in p'''""'^" 

 the manner described bv 11 c 

 The change which W ei.Mii; - 

 a rotation of the cephalic lobes as upon an axis, 

 the latter part of the sixteenth and the earl\' ])a- 

 teenth days. This change is best followed by 

 relations of the brain lobes and of the tendon 

 the rest of the cephalic region. At its close the 

 have pushed over the mandibles in such a way as 

 the mandibular pleurites. The mouth parts assi 

 definitive position, and the head is practicall\- to 

 1^ not until much later that the sclerites 1ki\c b - 

 nized as to be perfectly distinct. 



cockroach has been de>,ci ibed and tmuud In Mi 

 and, more fully, by Conistock and Koc hi (:0- 



^i^ing sclerites m ditterent insects. 



In the adult l^latta the body ot the tenlonuir 



