582 



CAROLINE B. THOMPSON 



ing a network of intracellular canals that open into the lumen 

 of the gland by pores in the cuticula. In surface views of the 

 soldier head strands of muscle fibers seem to be connected with 

 the lateral and posterior surfaces of the frontal gland, and, as 

 was stated above, an opening in the cuticula of the head above 

 the gland may be clearly seen. Although no secretion was 



Fig. 7 Frontal section of the frontal gland of a worker. B.m., basement 

 membrane; ms., mesenchyme; /, epithelial cells. Homog. immers. 1.8mm., oc. 6, 

 reduced one-fifth. 



actually observed in the lumen of the gland, the intracellular 

 canals and the pores in the glandular cuticula seem to indicate 

 that the frontal gland in the soldier is in active secretion. 



5. The worker. The frontal gland of the worker as seen in 

 surface view (fig. 11) is very small and is surrounded by an 

 empty space. Sections (figs. 7, 25) show that this gland, al- 

 though bearing a morphological resemblance to that of the 



