and Laboratory Methods 2537 



first estimated by addition of acetic acid, as above, and the freezing point and 

 specific gravity obtained after boiling are employed in the estimation of sugar. 



R. p. 



Burker, K. Eine einfache Methode zur Gewin- No satisfactory method of getting blood 

 nung von Blutplattchen. Centralbl. f. plates in large numbers, and unmixed 

 ^ ■ • 37, J . 9 3- ^j(.]^ either white or red corpuscles, has 



hitherto been described. Burker states that the following simple procedure 

 works very satisfactorily. The drop of blood is obtained by puncturing with a 

 lancet or better with a Fancke's needle the skin on the tip of the finger, which 

 has previously been thoroughly cleaned with ether-alcohol. The drop is allowed 

 to fall through as short a distance as possible onto a smooth piece of hard paraf- 

 fin, or a slide coated with paraffin. The blood drop will not spread on the paraf- 

 fin, but takes as nearly as possible a spherical form on account of its surface 

 tension. The paraffin plate bearing the blood drop is placed at once in a moist 

 chamber, in order to prevent clotting. There immediately begins in the drop a 

 natural separation of the elements in the blood, on account of their different 

 weights. The red and white corpuscles sink to the bottom, while the blood plates, 

 being specifically the lightest elements, rise to the top. If, after from 20 to 30 

 minutes, a perfectly clean cover-slip be barely touched to the uppermost surface 

 of the drop and at once raised again, it will bring away a small drop of serum 

 containing a large number of blood plates, and but very few corpuscles. The 

 cover is at once placed on a slide for examination. Clotting begins very soon 

 on the slide and fibrin threads may be seen in process of formation. r. p. 



Moore, Anne. Some Facts concerning Geo- ^iss Moore finds that positive geo- 

 tropic Gatherings of Paramecia. Amer. tropism may be induced in Paramecia 

 Jour. Physiol. 9: 238-244, .903- ^y (a) Mechanical shock. The effect of 



shock takes place quickly and is lost quickly, (b) Reduction of temperature. 

 Atl°C. the effect is marked, and takes place quickly. In a comparatively 

 short time, the animals may adapt themselves to the low temperature and lose 

 the sense of geotropism. (c) Increase in concentration of the surrounding 

 medium. This factor is not so constant as the other factors, and the effect not 

 so marked, (d) Lack of food. The effect takes place slowly and is lost slowly. 

 Negative geotropism may be induced by a plentiful food supply and by an 

 increase in temperature within limits. It is pointed out that these reactions may 

 be of some importance in the life history of the organisms. r. p. 



vr c ,. c- ^- ^ ■■ , ^^ n- , The surf ace arca of t he cerebell um has 

 Kreuzfuchs, S. Die Grosse der Oberflache 



des Kleinhirns. Arb. a. d. neurol. Inst, zu not up to this time been exactly deter- 



Wien 9: 274, 1903- Ref. Centralbl. f. j.^ined, and the work of Kreuzfuchs 

 Physiol. 17: no, 1903. 



makes a noteworthy contribution in this 



direction. In making the determination the vermis and hemispheres of a cere- 

 bellum were separated, and serial sections of the three parts were made. The 

 sections were from 200 to 300 mikrons in thickness. The sections were put 

 into anilin oil, projected with an Edinger drawing apparatus, and the projected 

 peripheral outlines measured with a map-measurer (" Curveometer "). As all 

 the sections were made as nearly as possible at right angles to the surface of the 



