SSLT.aSTTsST progress of microscopical science. 249 
without removing the epithelium. If the fluid is allowed to act longer 
on it, it penetrates the epithelium, and causes the muscle-nucleus to 
shrivel and assume the well-known staff-like shape. The primitive 
form of the nucleus is also very well preserved in the weak chromic 
acid solution. For further particulars we refer our readers to the 
interesting paper itself, which is to be found in the concluding part 
of the fourth volume of Max Schultze's ' ArcMv fiir MikrosJcopische 
Anatomie.' 
The AmpuUce, or Mucus Canals of the Selachia, have been re-examined 
by Herr Franz Boll. They are called by the author Lorenzinian 
AmpulloB, after their discoverer Lorenzini, to distinguish them from 
the ampullas of the organs of hearing. — Max Schultze's Archiv fur 
Mih'osJcopische Anatomie, vol. iv., part 4. 
Siehold and Kolliher^s Zeitschrift fiir WissenschaftUche Zoologie. — 
The last number of this Journal contains the following memoirs. — I. By 
Professor E. Claparede — Studies on the Acarina : (1.) Contributions to 
the Knowledge of the Comparative Anatomy and Development of the 
genus Atax. (2.) On the Development of the genus Tetranydrus. 
(3.) On the Development of Tyroglyphus. (4.) On the genus Hy- 
popus (Duges), as a male form of some Tyroglyphi. (5.) On the 
Development of Hoplophorus. (6.) On the Anatomy and Develop- 
ment of Myohia muscuU (Pediculus muris musculi, Schrank ; Myobia 
coarctata, Heyden). (7.) On Myocojptes musculinus {Dermaleichus mus- 
culinus, Koch). (8.) " Flir Darwin," Considerations on the Claws of 
some Acarides. II. By Herrn Fritz Ratzel and Dr. M. Warschawsky 
— On the Development of the Earth-worm (Luhricus agricola, Hoffm.). 
III. By Herr Dr. Fritz Ratzel, of Carlsruhe — Contributions to the 
Anatomical and Systematic Knowledge of the Oligochaeta. 
On Ciliary Motion. — A memoir of 178 pages by Herr Th. W. Engel- 
mann on this subject is to be found in the ' Jenaische Zeitschrift fiir 
Medicin und Natur Wissenschaft.' It includes the description of a 
gas- chamber for microscopical investigations, by which the action of 
different gases upon an object under the microscope can be observed. 
The gas-chamber allows of the electric current being passed through 
the object in the different gases; it can be used with the highest 
powers, and can be applied at once to any microscope. 
On the Blood and other ' Suspension-fluids. — Herr Alexis Schla- 
rewsky, of Moscow, has contributed a paper to Pfliiger's ' Archiv fiir 
Physiologic ' on the phenomena observed during the flow of blood, or 
analogous compound fluids, or artificial mixtures of liquids and solid 
particles through capillary tubes ; and another paper to the same, en- 
titled "On the Extravasation of the White Corpuscles." 
Researches with the Microspectroscope, in Pfliiger's ^Archiv fiir 
Physiologic,' by Herr S. Strieker, contains nothing of moment which 
has not already been worked out by Sorby. 
Microscopic Examination of the Vesuvian Lava of 1868. — Herr 
Felix Kreutz has made a microscopic investigation of the lava which 
flowed from Vesuvius during the eruption in October last. Besides 
