"The female rats were sacrificed by carbon dioxide asphyxiation on GD 20. A gross necropsy of the thoracic, abdominal, and pelvic viscera was performed and any gross lesions were preserved in neutral buffered formalin for possible histologic examination. Uteri of apparent nonpregnant rats were stained with 10% ammonium sulfide to confirm absence of

implantationsites (Salewski 1964). The number of corpora luted in each ovary was recorded; the uterus was opened and the number of live and dead fetuses as well as number of early and late resorptions were determined. Each fetus was weighed, sexed, and examined for any gross external abnormalities. Live fetuses were sacrificed by intraperitoneal injection of Beuthanasia-D Special (Schering-Plough Animal Health). Approximately one half of the fetuses in each litter were fixed in Bouin's solution and subsequently examined for soft tissue alterations using an adaptation of Wilson's sectioning technique (Wilson 1965). The remaining fetuses in each litter were eviscerated, cleared, stained with alizarin red S (Staples and Schnell 1964), fixed in alcohol, and examined for skeletal alterations."

Clinical observation and other proportion data were analyzed using the variance test for homogeneity of the binomial distribution (Snedecor and Cochran 1967a). Continuous data (e.g., maternal body weights, litter averages for resorptions, fetal ossification site data, etc.) were analyzed using Bartlett's test of homogeneity of variances (Sokal and Rohlf 1969a) and the ANOVA (Snedecor and Cochran 1967b), when appropriate (i.e., if Bartlett's test was not significant p>0.05). If ANOVA was significant, Dunnett's test (Dunnett 1955) was used to identify the statistical significance of the individual groups. If the ANOVA was not appropriate, the Kruskal-Wallis test (Sokal and Rohlf 1969b) was used, when less than or equal to 75% ties were present. In cases where the Kruskal-Wallis test was statistically significant, Dunn's method of multiple comparisons (Dunn 1964) was used to identify the statistical significance of the individual groups. If there were greater than 75% ties, Fischer's exact test (Siegel 1956) was used to analyze the data.

F1 Male And Female Crl: CD BR Rats