Vibrissae and genetic background: their role in a water submersion task with mice

Four experiments are reported which demonstrate that mice, deprived of their vibrissae and from different species and strains representing inbred, hybrid, and four-way cross genetic backgrounds, are impaired in their survival response on a water-submersion task in water of 105°F and with a tail weight of 2 gm to 30 gm of body weight. Although wide differences between groups are observed in rime to submersion with or without vibrissae, there is a trend for mice from groups of greater genetic heterogeneity to have longer time to submersion scores than inbred or genetically homogeneous groups. Handling, which was a necessary procedure in removing the vibrissae, is found to also reduce time to submersion when handling occurs without removing the vibrissae. Prior water submersion experience does not influence retest submersion scores.

RAMAN SPECTRUM OF CRYSTALLINE AND LIQUID SO2

The Raman spectrum of crystalline sulfur dioxide has been recorded at several temperatures between 9 and 185 °K. The main features are in accord with those predicted from the factor group analysis for the known structure of the crystal. Additional peaks were also observed, some arising from isotopic species and lattice fundamentals. As an aid to the assignment of several other bands, the spectrum of the liquid has also been recorded to distinguish the specifically crystalline features. Possible causes of these extra peaks, such as combinations with lattice modes, crystalline defects, and impurities, are briefly discussed.