METHODS FOB OBTAINING MEASUREMENTS \.\l» DOSAGE. 27 
This method might be practicable with a medium-sized tree, 
but for trees of Large size, especially seedlings, which arc sometimes 
more than 30 feet in height, its use would doubtless prove difficult, 
and for field operations multiplication of apparatus should be avoided 
as far as possible. 
WITIIOI T Ml' \i: \ II B. 
The Woodworth system. — The first scheme, so far as the writer's 
knowledge goes, for obtaining the measurements and dosage of 
trees without the use o\' apparatus was suggested by Professor 
Woodworth. This method consists of marking od the tent, on two 
opposite sides and parallel with the edge, a series of lines winch are 
placed at such distances from the center of the tent that they will 
correspond with differences of i ounce in the dosage of trees of the 
average shape. Upon each i^ these lines are marked three num- 
bers; the first indicating the dose (in ounces), the second the cir- 
cumference on which the dose is based, and the third the amount 
the dose must be varied when the actual measured circumference 
IS greater or less than that marked on the lent. For trees having a 
circumference greater than the average between the second figure 
on the line that is nearest the ground on one side of the tent and 
the second figure on the corresponding line on the opposite side, 
the average dose is increased for each additional yard of circum- 
ference by the amount (in ounces) given by the third figure on the 
line; for trees Inning smaller circumferences the figures are corre- 
spondingly decreased. 
Although the system is fairly accurate, its adaptability for use 
under the present condition of fumigation in southern California is 
somewhat questionable. The amount of calculation required to 
ascertain the dosage for each tree gives large chance of error and is 
wasteful of time. The possibility of error is still further increased 
through the necessity of varying the dosage for different species of 
scale-insect>. 
The Morrill system. 1 — Dr. A. W. Morrill, in the course of his 
work against the white fly (Aleyrodes citri R. & II.) in Florida, has 
devised a method of marking tents which is easily the most practi- 
cable yet proposed for obtaining the distance over the top of a tented 
tree. Although apparently a. modification of the idea presented in 
the Woodworth method, it is really quite different. In the Wood- 
worth system the actual dosage is calculated from the figures on 
the tent. The Morrill system is merely a rapid and simple way of 
obtaining the distance over the top <>f a tented tree. 
a Bui. 152, Univ. of Cal. Agr. Exp. Sta.. L903. 
&Bul. 7G, Bur. Ent. U. S. Dept. Agr., 1908. 
