120 BULLETIN 903, U. S. DEPARTMENT OF AGRICULTURE. 
swimming around in circles, but those at the bottom remained almost 
motionless unless disturbed. 
To sum up, it appears: (1) That eggs of radicicoles hatch readily 
in water, floating and sunken; (2) that the newly hatched larvae 
may live for more than a week submerged, or on the surface film; 
(3) that these larvae are capable, at least after four days of exposure 
to water, of fixing upon roots and developing in a normal manner. 
Further proof of the ability of young phylloxera? to live submerged 
occurred in an observation made from September to November, 
1914. A Eiparia cutting had been placed in a glass vial in the 
laboratory. Immediately a callus formed, and many rootlets grew 
around the inside of the vial. On September 15, 20 eggs of radici- 
coles were floated on the water surface. None of the resultant larvae 
persisting, more eggs were floated October 10. October 12 the water 
had evaporated, and four days later two young larvae had settled. 
These had hatched after the water evaporated. About 1 inch of 
water was then poured into the vial to cover completely all the root- 
lets and the two phylloxerae. October 22, three larvae were observed 
under water, one of which had been fixed since October 16. October 
27, there were visible under water, besides the original larvae of 
the 16th, six additional larvae, five of which were settled. October 
30 all seven observed on October 27 had settled and an eighth was 
visible moving over the rootlets. A small tuberosity had been set 
up by one of the phylloxerae. All the unhatched eggs had died. It 
was noted that when the insects were exposed to sunlight they moved 
their appendages actively. November 2, three settled larvae were 
visible. These included the individual on the tuberosity and the 
one which had settled October 16. All others were dead. November 
10 the only survivors were the original settler and the individual 
on the tuberosity. Shortly after November 20 all disappeared. 
Thus one individual, destined apparently to hibernate, persisted more 
than a month fixed on a root under water, and several others lived 
under water from 3 to 14 days. 
There also exists the possibility of infestation by seepage. On 
vineyards of porous soils young larvae on the surface may be drawn 
into the soil in time of a storm or irrigation. Also on steep hillside 
vineyards in the springtime, when heavy rains may fall or when a 
rise and fall in the " water table " may occur, a seepage infestation 
may take place. Any artificial irrigation during the months June 
to October invites the spread of phylloxerae because in this period 
phylloxerae occur above the surface of the soil or are active on surface 
rootlets. 
CUTTINGS AND ROOTED VINES. 
In European countries where a small percentage of the winter 
eggs are deposited under the bark of yearling wood there is a slight 
