The Use of a Microbalance in Putting up Uniformly Sized Batches of Heterodera Cysts for Experiment.

Tests were conducted using a capillary microbalance to estimate the errors introduced as a result of weighing out replicate cyst batches in place of counting.Experiments with differently sized samples showed that the normal relationship between sample size and accuracy applied to such cases, the error for samples of 100 cysts being usually of the order of less than 10%. There is some evidence that the errors in cyst number introduced as a result of weighing is reflected by an increased error in the larval count, although under the conditions of experiment the increase was barely significant. It is suggested that if replication is increased by 50% or 100% then errors due to inequality in cyst numbers are more than counteracted.