1gr1] MACDOUGAL—OVARIAL TREATMENTS 251 
the behavior of the fluid and its possible contact with the main 
or accessory reproductive elements. First of all, it is important 
to determine whether the solutions affect the egg cells or the 
pollen elements, and a number of tests were made with dyes 
for this purpose. The large ovaries of the giant cactus (Carnegiea 
gigantea) offered some excellent opportunities for testing these 
points. 
The introduction of reagents into the ovaries of this plant was 
accomplished by thrusting the tip of a needle of a syringe diago- 
nally downward into the cavity through the wall, and then by a 
steady pressure of the plunger perhaps as much as 0.4 to 0.6 cc. 
of solution was forced in, setting up a pressure that in some instances 
increased the external dimensions of the ovary, and the withdrawal 
of the needle was often followed by the ejection of some of the 
fluid, but the high turgidity of the walls soon closed the aperture 
or perforation. 
The flowers of Carnegiea gigantea ordinarily open in the morn- 
ing and attract a variety of bees and small gnats, the former 
Probably being instrumental in pollination. Plants taken to the 
New York Botanical Garden in 1902 did not set seeds unless 
pollinated by hand. The flowers open in the morning and close 
with the day when the temperature is above 80° F., but on cooler 
or cloudy days the flowers may remain open during a part or 
all of a second day. 
The style is as much as 5 or 6 cm. in length, and the pollen tube 
arising from grains falling on the stigmatic surfaces seems to take 
nearly a day in effecting fertilization, although exact observations 
on this point could not be made. It was deemed best, therefore, 
to inject solutions into the ovaries at any time between Io A.M. 
and 4 P.M., thus securing the possibility of affecting the egg appara- 
tus, or the pollen tube as it advanced. 
The introduction of methyl blue at this time was followed by 
its absorption by the inner walls of the locule, and its conduction 
to the apex of the ovarial cavity at the base of the style in such 
manner that entering pollen tubes must pass through the impreg- 
nated layer, and would be subject to the action of free coloring 
agent, whether traveling intracellularly or intercellularly. That 
