1918] WEIR—RAZOUMOFSKYA 7 
been demonstrated that size and color of flowers, stem, fruit, form 
and division of calyx lobes, slenderness and length of plant, com- 
pactness of individual colo- 
nies of the northern form 
depend upon age of the 
plants and of the infection, 
nourishment, condition, loca- 
tion, and species of host. In 
view of these results it seems 
desirable that the diagnostic 
characters as now employed 
in the separation of the large _ 
plants on yellow pines should Fic. 5.—R. cryptopoda on Pinus chihua- 
be substantiated by a large huana: sift reduced one-half.—Photo- 
: raph by G. G. Hepccock. 
number of cultures before 
they can be held specifically distinct. Experiments involving the 
transfer of seeds of the northern and coast plant from its various 
hosts to Rocky Mountain 
yellow pines, and vice versa, 
in their respective regions 
should be of some value in 
determining the validity of 
the two alleged species. 
R. occidentalis abietina 
Engelm. (figs. 7, 8) is a large 
form of mistletoe found on 
Abies throughout California, 
Washington, Oregon, and 
Idaho. It closely resembles 
the large mistletoes on yellow 
pines and is described as a 
Fic. 6.—R. campylopoda on Pinus varietv of the form R. cam py- 
ponderosa as it often appears growing from en a 
an advancing cortical stroma in branches of lopoda (figs. a 2, 6) (Arcew- 
witches’ brooms: plants pistillate, mature. ‘obium occidentale). The 
plant is not so large as the 
latter, but both have the same color variations and bloom and 
fruit in the same period. The facts that it is usually found in 
