162 THE EARLY STAGES OF TABANIDiE 



about in a restless manner, constantly vibrating the balancers and 

 flapping its wings, while the distended abdomen becomes reduced to 

 more normal proportions. 



The meconium, which is deposited in large quantities, is pale brown 

 in color, rapidly changing to amber, then becoming clear. The pri- 

 mary, heavier excretion appears decidedly oily in nature, when 

 examined with the microscope. 



In from fourteen to twenty minutes, voluntary flight takes place. 

 This is at first tentative, the insect alighting upon the floor about a 

 meter distant. After a minute of rest, flight is resumed, the fly 

 escaping through the open window. 



The puparium left behind shows certain points of cleavage which 

 prove to be very constant. There is a dorsal slit on the median line 

 of the thorax which extends nearly the length of the notum. Another 

 slit extends midway across the orbital region through the genai to 

 the wing pouches. A third slit extends between the two wing en- 

 velopes, and a slight one behind the prothoracic spiracular tubercle. 



In the thirty- two emergences recorded, the males preceded the 

 females by an average of half a day. The males spent from three 

 to seven days in the pupal stage, averaging five and one-half days, 

 while this period required four to nine days with an average of six 

 days in the female flies. 



Bainbridge and Fletcher (1914) observed Tahanus striatus near 

 Madras, and give the following statements which may serve to com- 

 plement Mitzmain's work in as far as it seems based on field obser- 

 vation : 



"Eggs are laid in a large mass, usually on a leaf or twig overhanging water 

 into which the young larvce drop on emergence, thence-forward leading an 

 aquatic life burrowing in the mud at the water's edge and feeding on worms or 

 living or dead insects. The full grown larva is 40 to 50 mm. long, dull whitish, 

 elongate, tapering at each end with protuberances at the edges of the segments. 

 When full fed it leaves the damp mud at the water's edge and after a quiescent 

 period pupates in the earth above water-level." 



An egg mass of Tahanus striatus on a paddle leaf is figured (Plate 

 2, Figs. 22 and 23). 



Patton and Cragg state that Tahanus striatus oviposits as a gen- 

 eral rule on blades of grass, pieces of stick, etc., at the edge of a river, 

 stream, or pond. 



