1917] Hungerford—Life-History of Mesovelia mulsanti White 79 
marks the exposed end of the egg as it lies in situ in the stem of some 
plant. 
Color: When first laid, white; in the course of two or three days 
it has become watery transparent with portions of the embryo 
beginning to take form. These eggs buried singly as indicated 
above are shown in the drawings (PI. I, Figs. 5 and 7). The 
exposed end of the egg shows up as a shiny membranous circular 
spot on the surface of the plant which bears it and is visible to the 
naked eye. This spot, though clear white when first laid presents 
at about the second day a very faint ring of pink which darkens 
to a deep pink after twenty-four hours. In the course of another 
day or two this gradually fades and two days before hatching the 
deep red eye spots may be seen through clear stems in the position 
shown in Fig. 7 
The egg stage lasts seven to nine days. At hatching the young 
nymphs, still enclosed in their embryonic membrane, work their 
way up through the little circular openings of the stem. This is 
a remarkable feat considering the size of the nymph and the size 
of the hole but is aided materially by the peculiar backward pointed 
pegs on the thin embryonic membrane. When well out of the 
stem this membrane is cast and the nymph takes its place upon 
the water. 
First Instar. 
Size: See the table presented below. 
Color: When first hatched it is white with red eyes darkening 
to amber and green as it ages. To the unaided eye it is greenish 
brown. Thus it is much darker than the older nymphs, quite 
distinct in coloring. The tips of the appendages are dark while 
the limbs themselves are pale. 
Structural Peculiarities—The general form is stouter and more 
robust than that of the later stages. The body and limbs are 
clothed with hairs and bristles as shown in the Fig. 4. The head 
and thorax bear a few stout bristles and the antenne bear on the 
first segment several (usually 3 or 4) stout bristles directed mesally 
and the terminal segment is thickly covered with fine hairs. The 
limbs, besides bearing many hairs possess a number of black 
bristles arranged as follows: One stout bristle is prominent near the 
distal end on the anterior margin of the meso- and meta-thoracic 
