3IO The Ohio Naturalist. [Vol. XIV, No. 7, 



The Egg. Figs. 3 and 4. 



The egg is cyhndrically oval, slightly narrowed posteriorly; 

 dorsal side, concave; ventral side, convex; lateral sides, somewhat 

 parallel. A gelatinous cap covering the micropyle is situated up- 

 on the anterior end. Length .68 mm to .75 mm. Width .IS mm 

 to .2 mm. (10 eggs). 



The chorion is smooth, partially transparent, pearly white. 

 A delicate mosaic work of regular pentagonal facets was observed 

 upon a small portion of the chorion of one egg. The others were 

 covered with some material which probably obscured the sculptur- 

 ing. 



In the breeding jars the eggs were found on bacon, sweitzer 

 cheese, ham and slightly putrid beef-steak, rarely in clusters, be- 

 ing, as a rule, scattered singly over the surface pointing in various 

 directions. No eggs were ever found upon the sides of the jars. 



Duration of the egg stage 23 to 54 hours. Temperature' range 

 60° to 80° F. Normal saline solution will hasten the hatching 

 process. The chorion collapses after the larva emerges. 



The Larva. Figs. 6-14. 



The Larva may be observed through the partially transparent 

 chorion several hours before hatching. When ready to emerge 

 the anterior end of the egg shell is pulled back slowly, receding about 

 4:^2 t^, and is then suddenly shoved forward. After several of these 

 backward and forward movements, the egg-shell splits across 

 the anterior end and back on the sides a distance of about .2 mm. 

 (Fig. 5.) Through the opening thus made the larva emerges. 

 The larvte arc active immediately after they emerge from the 

 shell. 



The newly hatched larvae measure, when fully extended, from 

 .8 to .88 mm. long; when contracted .7 to .75 mm. long. Width 

 .1 to .15 mm. To the unaided eye, the young larvae, except for 

 the black chitinous mouth parts, are white. Under the binocu- 

 lar they have a dusky granular appearance. Through the partial- 

 ly transparent integument the two main tracheal tubes, for their 

 entire length, are visible. 



In shape, the larvse are cylindrical, blunt at the posterior end, 

 tapering gradually toward the anterior end. The segments are 

 as distinct and of the same number as in the mature larvae. The 

 integument is smooth and devoid of vestiture, except for three 

 faint transverse, irregular rows of black chitinous teeth or spines 

 on the antero — ventral portion of each of the 7 segments, posterior 

 to and including the sixth segment. 



The cephalic segment is bilobed, each lobe bearing on its 

 antero — dorsal surface an antennal tubercle. Between the oral 

 lobes extend the paired falcate mouth-hooks. The cephalo- 

 pharyngeal skeleton extends nearly the length of the first two 



