JOURNAL OF ENTOMOLOGY AND ZOOLOGY 39 



Returning- now to the head region we find that the supra- 

 esopliageal ganglion is fused witli the suljesophageal in its for- 

 ward region. Two prominent iirojections extend forward from 

 the thickest mass of tlie ganglion from about the region of tlie 

 connectives ; these are the antenna! lobes. From the ends of 

 each of these the antennal nerve of each side takes origin and 

 rims forward as a large trunk up into the antenna. From the 

 slightly broader portion of the ganglion, above and quite near 

 its connection with the subesophageal center at the base of the 

 antennal lobe, laterally nerves on each side connect the brain 

 with the group of large sensory cells of the postantennal organ. 

 The connections and positions of these are very mucli like those 

 described by Becker '10, and shown in his Fig 27. Tliese sense 

 cells were much as described by this author. The little masses 

 in these cells called by Becker "Zwischensubstanz", were very 

 evident. These last usually stained almost as dark as the fat in 

 various parts of the body. Back of the region of the post- 

 antennal sense cells the liroadest portion of the brain is reached. 

 In this brain, as in one figured Ijy Becker, the caudal end of 

 the ganglion is tri-lobed with the middle portion slightly 

 l)i-lobed. 



The subesophageal ganglion caudad of the connectives with 

 the brain separates more and more from the upper nerve center 

 as the thoracic region is approached. The figure of Boettger 

 comi)iled from sections of the head ganglia of Lepisma is not 

 far from the condition of the centers of the head of ApJiorura. 

 From the sides of the subesoi)hageal ganglion three main nerve 

 trunks take origin. These from the head end towards the 

 thoracic region may be homologized as follows: mandibular, 

 maxillary, and labial branches such as found in other insects. 



In the consideration of the sui)raesoi)liageal ganglion no men- 

 tion was made of an ocular l>rauch or lobe, because there are 

 no eyes and no ocular part of the brain was recognized. 



With some difficulty a clypeolabral trunk was distinguished. 

 This nerve is rather small. It takes origin from the base of the 

 antennal lobe near where it joins the supraesophageal ganglion 

 and near the connective on each side. Its origin is more ven- 



