64 INSECUTOR insciti.ih; menstruus 



broadest circumference by a gelatinous substance which helps 

 to keep the mass afloat. A little less than one-third of its length 

 lies submerged, the remaining portion being above the water. 

 The eggs on escaping from the female are of a distinct grayish 

 brown color, but in less than half an hour that portion which lies 

 exposed to the air above the surface of the water assumes a 

 dark steel blue appearance, the whole mass of individual eggs 

 simulating a honey comb or a collection of gun shells resting 

 on their bases. 



To the naked eye an individual egg shows an ovoid shape 

 elongated at both extremities with their broadest circumference 

 immediately above the junction of the blue and brownish por- 

 tions, the latter tapering rapidly v/ith a sharp and distinct curve. 

 The lower portion, which retains its color, is chitinous; the 

 other, which lies above the water, is brittle and "calcareous." 



Microscopically an egg is seen to consist of one portion a 

 Jittle less than one-third which lies submerged and which retains 

 its brown color, and another portion which rests above the 

 surface of the water over which there is a definite but loosely 

 adherent capsule, studded with numerous translucent peduncu- 

 lated and sessile tubercles, arranged in regular rows and con- 

 taining air (Plate III, figs. 2, 3, 5). This investing capsule 

 enfolds the underlying portion of egg and in the fresh prepara- 

 tion is seen to extend to the junction of its lower and middle 

 third. It is, however, absent along a line running from below 

 its apex to its base, leaving bare a space gradually increasing 

 in extent from above downward and with its extremity curved 

 on either side. Along this bare area the brown egg shell can 

 be seen. The change in color from brownish to dark blue 

 affects this capsule only and not the egg shell. Shorn of its 

 capsule the underlying egg shell is seen to consist of a brown- 

 ish outer layer made up of definite circular strands enclosing an 

 inner thin delicate layer surrounding the yolk substance which 

 bathes the larva cells and subsequently the larva. No oper- 

 culum can be seen. 



The larva hangs with its head downward in the floating egg 

 and in from eight to ten hours after oviposition ruptures that 



