Nos. 455-556.] 



HEAD OF BLATTA. 



logues a celui que nous decrivons maintenant qui 

 plupart des embryologistes a considerer, a tort cr 

 I'antenne comme un membre post-buccal." (]). 2.S9. 



Viallanes was influenced in his interpretation by 

 of the nerv^ous system of the adult, in which tlic deul 

 the ganglion of the antennal segment, is ck'arl\- pr- 

 also its commissure. 



More recently, Comstock and Kochi (: 02) lia \ c eh; 

 commonly accepted view. Believing that the cl\])( 

 sents the median field of the sternitc of the antenna 

 they argue that a study of the figures given In auth 

 ing a post-oral position of these appenchiges 

 a line connecting the two antennae would 

 behind the mouth it is by no means so ck a 

 of the rudiment of the antennal scleritc 

 does not abut against the procephalon. In 

 fact, the very figures given to support th. 

 view that the antennae are post-oral in th' 

 early embryo support the opposite view, 

 (p. 31.) 



A study of Blatta has served to con tin 

 the view of Zaddach. At the time of v. 

 first appearance of the antennas the st^Mi 

 daeal invagination has not yet mamfc^t 

 itself. Its position is marked, however, i 

 an area of rapidly proliferating cells (I 

 2, m). The antennal rudiments are clear 

 caudad of this area, and are thus at th. 

 earliest appearance post-oral (Fig- ^oi' 

 They increase rapidly in size, and at a stau 

 but slightly later than that represented ii: 



