IOWA ACADEMY OP SCIENCES. 
79 
left some questions which it seemed very desirable to follow up. 
In order to obtain winged forms and determine positively which 
of the annual grasses they migrate from, the following varie- 
ties: Barnyard grass, Panicum crus-galli; Old Witch grass, 
Panicum cappilare; Crab or Finger grass, Panicum songuinale; 
Foxtails, Setaria glauca and viridis, and some species of Era- 
grostis, were covered with large lantern globes during the fall 
of 1892. The globes were sunk into the ground around the 
plants and the tops closed by tying bunting over them. These 
traps failed to catch any winged forms, though at the time they 
were put out plenty of wingless forms could be found on the 
roots of the Barnyard grasses and Foxtails. It appeared from 
this that some mistake had been made, or that the work was 
not done with sufficient care. During the season of 1893, with 
a view to determine this matter, if possible, the ‘ ‘ Dogwood 
louse ” was bred in confinement and artificial transfers made. 
The wingless brood from the eggs was found on Dogwood or 
Silky Cornel {Cornus asperifolia, Michx.) May 17th, and con- 
fined by covering with cheese cloth. Young plants of Foxtail 
[Setaria viridis) were transplanted to flower pots and put in the 
green-house, lantern globes with tops closed with cheese cloth 
being put over the plants. In one jar a colony of the small 
field ant [Lasius hrunneus) var. alienus, was put. This was 
done because these ants are usually found with root lice. On 
June 3d winged specimens of the second (?) brood were found 
under nets on Dogwood and transferred to jars containing Fox- 
tail, by cutting ofi the twigs and inserting them into the dirt by 
the sides of the plants. They were left on the twigs because 
they are delicate to handle and, besides, in the case of the ants, 
it was a means of supplying the lice their natural food-plant 
for a few days till the ants could transfer them to the grass 
roots, in case the latter were essential to the migration. They 
have been observed carrying winged root lice out of doors dur- 
ing this season of the year. Both these transfers proved a 
failure, the lice refusing to colonize on the grass and dying. 
This may have been due to confinement, but seemed to indicate 
the wrong species of grass. 
At the same time that the artificial breeding was being car- 
ried on observations were kept up in the field. On May 24 a 
root louse was found on Shepherds’ Purse [Capsella hursa-pasto- 
ris, Mench.) and Knot weed [Polyganum aviculare, L.), which 
resembled ScUizoneura, though of a different color than the 
