BRAIN OF THE 'WHITE ANT' 587 



Wasmann ('02), in describing the new genus Speculitemies 

 states that it is " Ausgezeichnet durch die grosse, unpaare Stirno- 

 celle, welche nicht nur bei der Imago, sondern auch beim Arbeiter 

 vorhanden ist." 



Now, although I am firmly convinced that the fontanel spot 

 with its opening is not an ocellus or simple eye, I feel that there 

 is considerable evidence that the frontal gland of the termites 

 may have developed phylogenetically from an ancestral median 

 eye and its ocellar nerve. In other words, the frontal gland 

 may have first arisen as a modification of the hj^podermis at the 

 point where the ancestral median eye was formerly situated, and 

 then may have extended inward into the head along the course 

 of the former median ocellar nerve, the proximal part of which 

 maj^ still persist in the nerve which I have termed provisionally 

 the fontanel nerve. 



The evidence in support of this view, gained from the study 

 of the different forms of L. flavipes, ^^^ll now be presented. 



1. The anterior surface of the frontiil gland of the n}inphs 

 and adults of the sexual forms hes in the same frontal \)hu\e as 

 the lateral ocelli. The posterior end of the frontal gland lies in 

 the region in which the lateral ocellar nerves enter the proto- 

 cerebral fibrous core. The frontal gland has therefore the same 

 linear extent as the lateral ocelh and the ocellar nerves. 



2. The nerves from the lateral ocelli run from the ocelli in 

 toward the median line on the outside of the brain sheath, directh' 

 beneath the h>T3odermis, then pierchig the brain sheath, they 

 run downward and backward within the nerve cell layer of the 

 brain, finally entering the fibrous core of the protocerebral lobes 

 at a definite point, namely: immediately behind the posterior 

 dorsal commissure. The fontanel nerve from the frontal gland 

 enters the protocerebral fibrous core in the median line, imme- 

 diately behind the posterior dorsal commissure, and, according 

 to the present theory, may represent the median ocellar nerve 

 (fig. 19). 



3. The lateral ocelli are derived from the hypodermis, and the 

 tips of the \'isual cells still lie in contact with and perhaps be- 

 tween the h^-podermal cells. The frontal gland is directly con- 



