渦鞭毛藻類の形態観察における倒立顕微鏡の利用について : 扁平な形態をした五種の渦鞭毛藻類の観察

以上倒立顕微鏡を用いることによって,極度に扁圧して,扁平な形態を有し,正立顕微鏡では全ての方向から観察することが極めて困難な5種の渦鞭毛藻類について,従来よく観察の行なわれている方向とともに,従来殆んど観察の行なわれていない方向から観察を行なうことができた。その結果,Ceratium furcaに就いては,従来文献に現われたことのない側面から見た像を提示することができた。また,Pyrophacus horolongicum, Ceratium triposに就いては,従来の記載が部分的に不正確なものであることを示し,新たな記載を加えた。更に,Dinophysis acuminata, Oxyphysis oxytoxoidesに関しては,従来の記載が非常に正確なものであることを確認することができた。

During about five years we have continued observational studies of Dinophyceae found in the Seto Island Sea, because they are not only very common in marine environments as phytoplanktons but are very important for the determination of the causative and composing organisms of the red tides. In the course of these studies we found that the utilization of the inverted microscope of the Le Chaterier type is much more advantageous for the observations of these organisms than the ordinary microscope. A fairly large number of organisms belonging to the Dinophyceae is, as is well known, compressed longitudinally, bilaterally or dorsoventrally, and when the preparations for their microscopical observations are made, these organisms tend to show definite tendency of directing towards the bottom one of these more or less flattered surfaces of the body. Most of the morphological studies of these organisms performed unto now, therefore, were restricted to observations from particular directions, such as; apical or antapical observations of Pyrophacus, lateral observations of Dinophysis or dorsal and ventral observations of Ceratium, for example. Cover glasses, which are indispensable for observations of high magnification with the ordinary microscope, are not necessary when we use the inverted microscope, because the object lens of the inverted microscope is set up on the underside of the stage, and so, the objects are observed from beneath through the slide glass. Furthermore, inverted microscope is designed to secure a larger space over the stage, keeping the luminescent source farther over the stage by means of a long-focused condenser. As a result of these constructional particularities of the inverted microscope, organisms can be manipulated while the observation on the slide glass with microneedles or other appropriate tools, and so, may much easier be observed from all the desired sides of the bodies. Thanks to the inverted microscope, we could show, for example, in this paper, together with their conventional images, lateral view of Pyrophacus horolongicum, a strongly longitudinally compressed species, dorsal and ventral views of Dinophysis acuminate and Oxyphysis oxytoxoides, typically bilaterally compressed species, lateral view of Ceratium furca, apical view of Ceratium tripos, strongly dorsoventrally compressed species, all of which were very difficult to observe with the ordinary microscope unto now.