Seaward movements of Atlantic salmon (Salmo salar L.) smolts through Red Indian Lake were studied using radiotelemetry and Carlin tagging. Movements of smolts through the lake occurred between the hours of 20:00 and 04:30 as determined from radiotelemetry. Carlin tagging revealed a net swimming speed ranging from 1.8 to 15.6 km/day; radiotelemetry revealed a rate of <1.0 to 11.2 km/day. Smolt movement through Red Indian Lake and other large insular Newfoundland lakes might be achieved through active migration as opposed to passive displacement. This aspect is discussed in the context of insular Newfoundland stocks for which extensive use of lakes by juveniles for rearing has been demonstrated.

Electromyograms (EMGs) from the corrugator, zygomatic and splenius capitis muscle sites and Beck depression inventory scores were obtained from 21 depressed in-patients shortly after admission and after two weeks in hospital. Contrary to the result of a previous study by other investigators, significant covariaton between depressive symptoms and corrugator EMG levels was not seen. However, consistent with a second finding of the previous study, initial corrugator EMG levels were shown to be significantly predictive of treatment outcome. Further, initial EMG from the zygomatic was also found to predict changes in depression. The explanation is unclear and further research is needed.

The migration of Schwann cells and their early association with axons were studied in transparent tadpole tail fins. Nomarksi optics revealed that in vivo these cells are pleomorphic, changing their shape by extending and withdrawing long, blunt pseudopods. Daily observations of the same fiber fascicles for a month or more combined with intensive short-term studies of other tadpoles showed that migrating Schwann cells move sporadically at rates of up to 114 μm/day. They are usually, although not always, in contact with one or more axons. In the electron microscope, these migrating cells are similar in cytoplasmic structure to others that have settled down and begun to spread along axons; however, they possess no basal lamina. Later, Schwann cells become more spindle-shaped and acquire a basal lamina. Schwann cell surface characteristics and the changes imposed by the presence of the basal lamina may be important in the establishment of permanent axon-Schwann cell relationships. In our living material we were unable to visualize the intricate, rapidly changing associations between Schwann cells and small axonal fascicles that precede myelination. However, they are probably more complex than Speidel's studies would indicate.

Electron micrographs of transversely sectioned sciatic nerves removed from newborn, 3-day-old, and 7-day-old rats were used to make montages of comparable areas in the marginal bundle of the posterior tibial fascicle. At each age, the number of axons, their diameter, their relationships with Schwann cell processes, and their degree of myelination were determined. Also, three-dimensional reconstructions of representative fiber groups in the newborn nerve were made from similar montages at 5 additional transverse levels. The results showed that outgrowth of axons and migration of Schwann cells continued after birth. Families of Schwann cells, each surrounded by a common basal lamina, formed the sheaths that subdivided the bundles. Axons to be myelinated appeared to progress radially from a bundle to a 1 : 1 relationship with a Schwann cell at the sheath's outer margin. Sheaths containing multiple Schwann cells became smaller and more numerous as axon bundles were subdivided. Almost all of the isolated Schwann cells, which were separated from their neighbors by collagen were myelinating single large axons.