This paper considers the practical problem in experimental chemotherapy where several treatment groups are compared with a control group in a multivariate covariance analysis and the observed data of mice are subjected to multiple comparison test. Mice infected with 50 cercariae of Schistosoma mansoni in unequal group sizes are challenged with some doses of Zingiber officinale extracts, Cremophore and Praziquantel. Data are available for the number of male and female parasites, weights of liver and intestine, and egg per gramme liver and intestine tissues. Proposed herein are multiple testing procedures such as, Tukey, Scheffe and Bonferroni based on two-sample statistics, each comparing an individual treatment with the control, for determining which treatments are more effective than the control. Newman-Keulís test corrobarates exactly with Bonferroni testís result, in the further analysis.