152 Journal of Comparative Neurology. 



broadest and extends the farthest posteriorly. Other general 

 details may be made out from the photographs. Below them 

 antero-laterally, below their whole posterior extent, or occupy- 

 ing the spaces between them and the rest of the proto-cerebron 

 are to be found ganglionic cells of various sizes, but mostly of 

 the small kind to be described elsewhere. There is also a small 

 mass of cells continuous with the mass between the upper por- 

 tion of each pair of cups, but which in the sections photo- 

 graphed appear to be cut off from the larger mass. Each fibril- 

 lar mass is outwardly clothed by a thin nucleated membrane. 



These are the bodies described by Dujardin as "lobes 

 a convolutions. " By later writers they are variously 

 called. Leydig (64) described them as "Lappen mit Wind- 

 ungen ;" Rabl-Riickhard ( 75) as " Rind Korper ;" Dietl ( 70), 

 Berger (78) and Cuccati ( ss) as " Pilzhutformiger Kor- 

 per ;" while Newton ( 79) introduced the name calyx, which was 

 adopted by Packard ( go) and Viallanes ( 87 and 88)- 



The bodies reach their highest development in the Hymen- 

 optera and are much larger in the social wasps than in the 

 honey bee. In Blatta the lateral walls of the cups are much 

 reduced, and in the Coleoptera the cup-like form is scarcely 

 recognizable, while in Forficiila and Acridian the fibrillar sub- 

 stance only forms a broad plate. Even this is scarcely, if at 

 all, recognizable in Dytisais. In Tabanns and Soniomya the four 

 folds are reduced to two and in the former of these genera are 

 scarcely to be distinguished by a comparison of their cells with 

 those surrounding them. In the Hemiptera they are not dis- 

 tinguishable at all, 



TJie Stalks of the Mushroom Bodies. 



From near the middle of the lower surface of each cup 

 a column of fibrillar substance passes into the main mass of the 

 proto-cerebron. In the bee these are much shorter than in 

 other forms. The inner one descends almost perpendicularly 

 downward for a short distance where it is joined by the one 

 from the outer cup, which is somewhat longer and has an in- 

 ward and somewhat forward course. In transverse sections the 



