CO2.plot <- ggplot(data = CO2, aes(x = conc, y = uptake, colour = Treatment)) +
    geom_point() +
    xlab("CO2 Concentration (mL/L)") +
    ylab("CO2 Uptake (umol/m^2 sec)") +    
    ggtitle("CO2 uptake in grass plants")
CO2.plot