Of white spruce and jack pine

waxes".Thus, the literature yields a rather sketchy picture of the leaf surface, its pores and waxy coating.a Light microscopes and a scanning electron microscope were used in this study.The internal anatomy and external morphology of the current .year'sneedles of 3+0 white spruce and jack pine seedling were examined.For the transmission light microscope (TLM), needles were fixed and embedded in paraffin wax before cutting in transverse and longitudinal sectioni ranging from 5 to 15p in thickness.The sections were stained and mounted on slides for examination and photography.For the scanning electron microscope (SEM) needles were cut into one centimetre lengths and mounted on aluminum stubs.They were then coated with a 200A layer of gold-palladium alloy.Their edges were later coated with a layer of silver to provide contact between the specimen and the stub.The specimens could then be examined and photographed.The advantages of the SEM over the TLM are a much greater depth of field (1 cm rather than 2% at 5OX), ten times the resolving power (150A) and ability to scan areas up to 1 cm2.An additional advantage of the SEM was that needles with an undisturbed cuticle could be compared with those washed in xylene to remove the wax.A defect of the TLM was the removal of both stomatal and epicuticular waxes during the fixing, embedding and staining process.e