228 -\YILSOX P. GEE. 



Length of Larva. ' Length of Cell. M .ength of Nucleus. 



4.5 mm. i8.4M 10.4/1 



6 mm. 24 fj. 12 n 



12 mm. 40 // 20. 6/1 



22 mm. 77 n 43-5M 



pupa 103. IM 63.5/1 



c;uly imago 94-3M 62.9/11 



cell is found in the imaginal stage. There is to be noted, how- 

 ever, a decrease in the total length of the oenocytes of this latter 

 stage, this being due, beyond doubt, to degeneration, manifest 

 signs of which are present. 



There are two sizes of oenocytes in the earlier larval stages. 

 One of the larger type, from a larva six millimeters in length, is 

 shown in the accompanying plate (Fig. 3). As already noted, 

 these large oenocytes are present in each of the abdominal seg- 

 ments, ventral in position, one occurring on each side. These are 

 many times larger than the oenocytes of the smaller type, and are 

 pressed rather closely against the hypodermis. In the earlier 

 stages of larval life, the greater comparative size makes these 

 oenocytes very conspicuous, while in the older larva this is not 

 so marked; in fact the smaller cenocytes in the oldest larvae 

 attain a size equal to or even greater than the formerly larger 

 ones. Careful examination of serial sections of these larger ceno- 

 cytes showed no traces of a duct leading from them. 



The smaller cenocytes are more numerous than the larger. In 

 the early larval stages, they are, as noted above, much smaller 

 than the other type, attaining, in the old larvae, an equal or 

 greater size. Their distribution in the body is, however, very 

 much more irregular. 



In the earlier larval periods the cenocytes appear much more 

 rounded in form than in the earlier stages. The nucleus shows 

 the same tendency. The cytoplasm presents a finely granular, 

 homogeneous appearance, and takes up rather evenly the orange 

 G and eosin. In these stages, however, the cytoplasm appear- 

 rather more dense than in the succeeding periods. 



Wheeler says with regard to the ceimcyies of an unidcniilM-d 

 phryganeid larva on which he worked that the nuclei contain no 

 nudeole. In a 4.5 mm. stage of Pl<tty/>/iyI<i.\- (IcsiatHilm;, stained 

 with safranin, a nucleole is seen to stand otn \ ery dearly (Fig. i). 



