382 SUMMARY OF CURRENT RESEARCHES RELATING TO 



cases it is necessary to stain for 48 hours, but gentle warming will 

 shorten the time required. This method is applicable to paraffin as 

 well as to celloidin sections, but they must not be fixed to the slide with 

 albumin or even with alcohol after Gaule's method. As a counterstain, 

 light green or indigo-carmine may be used. As an alternative method 

 Yastarini uses a creso-fuchsin and hematoxylin mixture. The author 

 finds that by Vastarini's methods, glycogen is well and sharply stained, 

 and the preparations do not fade quickly. On the other hand it may 

 fail unaccountably. 



Best's method is complicated, and the stock solution is difficult to 

 prepare. It is also unstable. Gage stains the tissue with a fairly strong 

 alcoholic solution of iodine, and by this means demonstrates glycogen as 

 a homogeneous and not a granular substance. This is probably due to 

 solution of glycogen by the iodine solution, and points; to a defect in the 

 method. 



The author uses a ferric chloride and gallic acid ink, prepared 

 according to a formula of Silbermann and Ozorovitz. Sections may be 

 stained either after fixation to the slide or by immersion in the stain. 

 To counteract simultaneous staining of the tissues, sections may be 

 stained first in para-carmine. It is in this case necessary thoroughly to 

 wash out the acid after this stain, in order to prevent subsequent pre- 

 cipitation of ink. Sections so stained have kept well for several months. 

 The author claims for this method the advantage of simplicity over 

 others described. 



Further Note upon Injection Methods.* — B. Mozejko, in a post- 

 script to his previous account of the application of injection methods to 

 the study of anatomical detail, points out that, for the demonstration of 

 the circulatory system in certain classes of animals, it is advantageous to 

 postpone injection almost until decomposition commences. This is the 

 case in Vermes, Gastropoda and Crustacea among the Invertebrates. In 

 Vertebrates the problem is complicated by the elasticity of the arterial 

 walls, and the coagulation of the blood which accumulates in the venous 

 system. In dealing with the former difficulty the author first of all 

 made trial of amyl-nitrite, according to the method of Oviatt and 

 Sergent, but found it unsatisfactory. He now uses a peptone solution, 

 with better effect. 



For the injection of arteries the best time is just the moment when 

 rigor mortis has passed off ; the tissues are still fresh but the arterial 

 walls no longer resist the passage of the injection material. It is, how- 

 ever, well to delay injection of the venous system until decomposition 

 has commenced. The blood clots are then partly or wholly liquefied. 

 The author obtained some of his best results by injecting reptiles (lizards 

 and crocodiles) two or three days after death. 



Staining Embryonic Nerve-tissues.f — In an investigation of the 

 development of the autonomic nervous mechanism of the alimentary 

 canal of the bird, Williamina Abel made use of Ramon y Cajal's silver- 

 nitrate method. This method consists in impregnating the tissue with 



* Zeitschr. wiss. Mikrosk., xxvi. (1910) pp. 542-7 . 

 t Proc. Roy. Soc. Edin., xxx. (1910; pp. 334-6. 



