C.P.S.—Its Strengths and Weaknesses

The following, a supplement to the annual report of the Board of Trustees of California Physicians'' Service that was published in the March 1961 issue of California Medicine, was delivered at the 1961 Annual Session of the House of Delegates by Dr. John G. Morrison, chairman of the board.     

Xizangia bartschioides (Hand.-Mazz.) D. Y. Hong——玄参科一新组合

虽然玄参科的马松蒿Xizangia serrata D．Y．Hong与齿叶翅茎草Petrygiella artschioides Hand．-Mazz．系同物异名,但齿叶翅茎草与翅茎草属其余4种植物在习性、叶、花萼等外部形态上有显著差异,在种皮方面的差异尤为突出。马松蒿属Xizangia 作为属的地位是合适的。因此,本文作了一个新组合,即XI-zangia bartschioides(Hand．-Mazz．)D．Y．Hong,而把Ptertrygiella bartschioides Hand．-Mazz．和Xizangia serrata D．Y. Hong均作异名处理。     

Electron microscopy—The U.K. involvement

The development of the electron microscope in the advanced form we know today is the result of a loosely organized but effective world-wide scientific and technological collaboration, that readily transcends national and cultural barriers. The birth of the subject was undoubtedly in Berlin but the United Kingdom has played a prominent part, sometimes in an accidental way, at critical periods in this development both at the scientific and manufacturing level. In 1927, for example, G.P. Thompson established experimentally the wave nature of the electron and its scattering and diffraction by thin foils. This followed his invention of the electron diffraction camera at a time when De Broglie's postulates on the wave of nature of the electron were not enjoying much support, even in his native France. C.W. Oatley in Cambridge University was successful in introducing the first commercial scanning electron microscope (SEM) where several commercial firms had previously failed. D. Gabor invented electron holography in a moment of boredom while watching a tennis match. The U.K. has also played a key role in fostering international collaboration by means of conferences and exchange visits between electron microscopists. The present paper concentrates on some of the critical developments that took place in the U.K. in the commercial development of transmission electron microscopy, in scanning electron microscopy and more recently in high resolution electron microscopy. These developments are placed as far as possible in a world-wide context.