+ BULLETIN 1112, U. S. DEPARTMENT OF AGRICULTURE. 
woods, while the genus Razoumofskya is found exclusively on 
conifers. Several species of the latter genus are rather common in 
- the western United States and in some localities have become very 
serious parasites. Razowmofskya eryptopoda, the western yellow 
pine mistletoe, is one of the most widely distributed of all the species, 
usually being found wherever the western yellow pine grows. 
(Pla Biea:) | 
Razoumofskya cryptopoda flowers in Arizona and New Mexico 
during April and May, and the fruit matures in August and Septem- 
ber of the next year. When the seeds begin to ripen, the berries — 
gradually turn downward on their pedicels until the base of each — 
berry when fully mature points upward. The gelatinous seeds when 
ripe are suddenly and forcibly ejected upward to a distance of several — 
yards by the giving way of a ring of tissue situated near the base of — 
theberry. Thismethod ofseed dissemination is common to all species — 
of Razoumofskya. Experiments and extended observations indicate | 
that the aerial portions of both staminate and pistillate plants die " 
‘and fall from the trees after one season of flowering and fruiting. | 
(Pl. I, Fig. 2.) | 
EFFECT OF MISTLETOE ON GROWTH OF HOST. 
The study of the effect of mistletoe on its host was accomplished ~ 
(1) by periodic measurements and observations of standing trees, — 
both infected and healthy; and (2) by detailed growth studies and | 
observations of infected and healthy felled trees. 
EFFECT ON BOLE OF TREE. 
Ninety-one healthy and mistletoe-infected trees between 10 and | 
30 inches in diameter breast high on three different areas within a 
radius of 5 miles of the Fort Valley Experiment Station were tagged, 
numbered, measured, and mapped in 1910 with the object of deter-_ 
mining the effect of mistletoe on the diameter and height-growth of — 
the host, the diameter growth of limbs, and the growth of the mer- | 
chantable contents of the bole. The diameters were measured with © 
a diameter tape at 1, 4.5, 17, and 33 feet above the ground. The 
total heights were measured with a Forest Service standard hypso- — 
meter. The diameters of 20 healthy and 34 mistletoe-infected 
limbs falling in different infection classes were measured on 18 __ 
standing trees with a view of determining the effect of mistletoe 
on the growth of limbs. The points of measurement at 6 inches 
from the bole of the tree and every 6 inches beyond this point were — 
marked by driving a 6-penny copper nail into the wood. All of the _ 
trees were remeasured in 1915 and were reclassified into four degrees — 
of mistletoe infection, according to the prevalence of mistletoe on — 
the tree, as follows: O, healthy trees without mistletoe; X, light | 
a 
feseaie|, 
