Koyama Fukusei Hospital

For the investigation of swelling wool the freeze-dry process used in histochemical fields was applied to various wool fibers. In our experiments, the swollen fibers were frozen in isopentan at -160°C and then dried at -60°C_??_-50°C for 2hrs. under the constant pressure at 1_??_5×10-2 mmHg. Such conditions prevented the deswelling of swollen fiber and kept the higher degree of swelling than that obtained with the usual drying method. An attachment to embed the sample fiber by the vinyl polymerization method was deviced to prepare the cross-sections of the frozon-dried samples.The results observed were as follows.i) The cross-section of merino wool fiber deformed from the original elliptic shape to circular one by swelling-treatment.ii) The more remarkable swelling of ortho-cortex was observed at the minor axis of crosssection.iii) The indented perimetric irregularity on the ortho-cortex appeared but not on the paracortex.