Gf. H. F. Nuttall 
119 
The lidless cells prevented the escape of the insects and confined them 
to an area corresponding in size with that of the hair-frame. Shortly 
after being fed, the female insects were placed upon the hair-frame in 
the cells and transferred to the stage of a binocular dissecting microscope 
placed at ca. 30° C. in a Nuttall microscope-thermostat. Until one 
of the females showed evidence that she was about to oviposit, only 
a minimum of light was allowed to enter the window, the latter being 
screened. Lice are very sensitive to light and care is necessary in 
regulating the degree of illumination required to see the insects well 
and not disturb them by an excess of light. The females which occasion¬ 
ally wander off the frame should be gently returned thereto with a fine 
brush. Incidentally I would mention that lice viewed under such cir¬ 
cumstances are infinitely more active creatures than might be supposed 
from ordinary observation. 
Fig. 3. Illustrating the process of oviposition upon a hair in Pediculus humanus 
(corporis), the insect being viewed through a microscope placed vertically. Drawing 
made from memory with the aid of dead specimens. The egg, a little under I mm. 
long, may serve as a scale. The female has just deposited the egg and is walking 
away with her gonopods still grasping the hair which is about to be released. 
The females ( corporis ) walked about a good deal at first but presently 
slowed down in their movements. One female was observed to bend 
the posterior portion of her abdomen downward so that it appeared 
somewhat concave in profile. She maintained this posture whilst 
relatively quiet, for a period lasting perhaps a minute. She then 
walked backward along a hair which was seen to glide within the fork 
formed by the posterior lobes of the last abdominal segment. The 
gonopods were flexed away from the body and against the hair; 
suddenly they were seen to slip around the hair and grasp it, almost 
at a right angle. Whilst gripping the hair with the gonopods the female 
retreated still further along the hair for a distance about equal to half 
her body length; she then came to a stop. What appeared to be a 
minute drop of hyaline fluid now appeared at the sexual orifice and 
after a few seconds the insect walked forward, the egg being com¬ 
pletely freed by her and cemented to the hair in the fraction of a second 
(Fig. 3). The female now released the hair from the grip of the gonopods. 
