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In this experiment, 141 split-rib grafts implanted into mature dogs showed the following: 1. All grafts were successfully transplanted in that they were incorporated into the host osteogenic bed. 2. Histological examination revealed osteogenic cells and osteocytes to survive only in fresh autogenous bone grafts. This osteogenetic activity was found to take part in the incorporation of the graft into the host tissue. 3. Fresh autogenous bone grafts were more readily tolerated by the host tissue than the preserved bone grafts or fresh homogenous grafts.

A comparison of threshold and slope efficiency is made for 2-μm laser action in Ho3+-doped YLF and YAG hosts at room temperature. Spectroscopic and laser properties of these materials are also discussed.

The profiles of seven major publishers of elementary-level tests were prepared from systematic ratings of the qualities of their tests. Meaningful rating differences among the publishers’ priorities were found and three types of publishers could be identified and described.

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In the politics of Florida a genuine liberal-conservative division is a rather difficult thing to find. Candidates for state offices are usually quite abundant and their separation into liberal or conservative groups is often difficult even for practiced political observers. In his recent study of southern politics, V. 0. Key observed of Florida, ". . . the electorate is not divided into groups with relatively constant attachments to well-known factions. Voters shift and the shape and membership of factions change."' Professor Key declares that for geographical reasons, because of northern immigration, and because of Florida's diversified economy and heavy urbanization, Florida is "different" from other southern states. He sees politics in Florida as characterized by a spirit of "every man for himself," and he dwells at length upon the multiplicity of political factions and the fluidity of their lines. Groupings in Florida politics, he says, are not permanent and do not center around issues.2 To a great extent these observations are quite correct. A survey of all election results in every state race shows little consistency; there is no apparent pattern of liberal-conservative voter alignment.3 Yet there exist in Florida liberals and conservatives as surely as in

The causes of tube breakage due to expansion of the charge during zone refining of chemical compounds are discussed. A new type of rotation-convection zone refiner which eliminates such tube breakage is described. Its main feature is that the molten zones fill slightly less than half the cross section of the tube, thereby producing solids with axial holes.

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NATURAL mRNAs contain specific signals for initiation and termination of protein synthesis1,2. To further understand these processes and their regulation in the cell, we have been screening mutants defective in translation of natural mRNAs but not of artificial templates.

The use of rhesus monkeys for studies of pulmonary infections is complicated by a high incidence of acariasis due to Pneumonyssus simicola in the lungs of imported animals. Treatment of this infestation with the organic phosphate compound Ronnel significantly lowered the incidence of active lesions. Another organic phosphate, Trichlorfon, failed to show a therapeutic effect under the conditions of this study.

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The experimental procedure for controlled vapor‐liquid‐solid, or VLS, crystal growth is discussed for silicon. The hydrogen reduction of was used as transport reaction, and gold as the liquid‐forming impurity. The stability of the liquid droplet, which is the main criterion for controlled VLS growth, is discussed in detail. It is shown that an adverse temperature gradient or an oversupply of silicon from the vapor may render the liquid droplet unstable, thereby terminating controlled VLS growth. Silicon crystals can be grown epitaxially on perfect or imperfect silicon substrates. The control of both location of crystal growth and of diameter and length of the crystals is demonstrated.