578 



CAROLINE B. THOMPSON 



the secondary, inner, layer is lacking above the lumen of the 

 gland. In figures 15, 16, 17, the deeper, central, part of the 

 gland is shown; figures 18, 19, contain the posterior outpocketing 

 of the gland, not connected with the margin in the figures, and 

 since these sections are considerably farther back in the series, 

 in the longest part of the head, the cuticula and hypodermal 



Fig. 5 Frontal section of the frontal or fontanel gland of a nymph with long 

 wing pads. B.ni., basement membrane; hyp., hypodermis; i.cu., inner cuticula; 

 o.cu., outer cuticula; /, long slender cells, probably not yet secretory in function; 

 2, swollen cells, probably glandular. Homog. immers. 1.8 mm., oc. 6, reduced 

 one fifth. 



cells are now some distance from the brain, and, for consider- 

 ations of space, are no longer included in the figures. Figure 

 20 shows the posterior wall of the frontal gland which ends in 

 the next section. 



a. The finer structure of the frontal gland. A closer study with 

 the immersion lens shows that the frontal gland is composed of 



