BRAINS OF THREE GENERA OF ANTS 531 



the ocellar lobes, some fibers crossing to the right, some to the 

 left, and so on down into the protocerebral core. The fibers of 

 the inner lobes enter the brain slightly anterior to those of the 

 outer lobes, as may be seen in figure 14, o.oc.L, from which the 

 inner lobes have disappeared, but fibers from the outer lobes are 

 curving into the anterior dorsal commissure.. In the queen of 

 Formica (fig. 13) there is no such relation between the anterior 

 dorsal commissure and the ocellar fibers. All four ocellar lobes 

 extend back to the posterior dorsal commissure, and are seen in 

 figure 23 lying dorsal to it, their fibers running down through it 

 into the protocerebral lobes. In this ant the fibers from the outer 

 ocellar lobes pass down anterior to those from the inner lobes 

 (fig. 23, i.o.L, O.O.I.). In the workers of Formica and Lasius the 

 four ocellar lobes blend into two masses above the posterior com- 

 missure, and their fibers run down through the commissure, in- 

 terlacing and crossing from one side to the other before entering 

 the prc^tocerebral fibrous core. In the males of the three genera 

 (fig. 22), the four ocellar lobes extend back to the posterior com- 

 missure; some of the fibers pass down and through it, others con- 

 tinue along the commissure into the protocerebral lobes. 



To summarize: in ants the ocellar nerve fibers may take three 

 different paths from the oceUar lobes into the protocerebral lobes : 

 (1) by way of the anterior dorsal commissure, queens of Lasius 

 and Camponotus, (2) through the posterior commissure, For- 

 mica queen, Formica and Lasius workers, (3) both through and 

 by way of the posterior dorsal commissure, males of the three 

 genera. 



The second path was described by von Alten for the female of 

 Bombus, and by Jonescu for the honey bee. 



Berlese ('07, p. 573), states: 



Airingresso di ciascuno dei nervi ocellare si trova un piccolo gaii- 

 glio (ganglio ocellare), dal quale precede il nervo ocellare. Secondo 

 Viallanes (Acridium) il nervo degli ocelli lateral! penetra nella parte 

 superiore e posteriore del lobo procerebrale corrispondente. II nervo 

 ocellare mediano e veramente pari, perche nel cervello si divide in 

 due branche divergent!, d! cu! ciascuna va ad unirsi al nervo laterale 

 corrispondente. 



THE JOURNAL OF COMPARATIVE NEDROLOGT, VOL. 23, NO. 6 



