246 SUMMARY OF CURRENT RESEARCHES RELATING TO 



liquid should not exceed one-tenth of the total capacity of the flask. 

 In three or four days growth is evident ;^in a week the colonies are 

 visible to the naked eye. 



Use of Magnesium in Stupefying Marine Animals.* — A. G. 

 Mayer finds that marine animals can be anaesthetized much more 

 rapidly if placed in an aqueous solution of MgS0 4 or MgCl 2 of three- 

 eighths molecular concentration. They then subside into complete 

 relaxation, and after an hour or two may be killed in any way without 

 becoming distorted through contraction. The method has been tried 

 with marked success, and seems specially suitable for stupefying highly 

 sensitive and contractile animals. 



Method of Examining Embryos from the Maternal Tissues of the 

 Rat. j — Y. Widakowich, in a contribution to the study of the embryology 

 of the rat, gives an account of his method of obtaining embryos and ova 

 from the uterus and Fallopian tubes of the female rat. In some cases 

 he examined specimens extracted from the maternal organs ; in other 

 cases, he prepared specimens of the tubes or the uterus with the con- 

 tained embryo and examined the tissues by means of serial sections. 

 Zenker's fluid and Schaffer's formalin-alcohol were the most satisfactory 

 fixing fluids. Sublimate-alcohol was tried, but made the specimens 

 very brittle. 



For imbedding such objects as Fallopian tubes containing ova, or 

 the uterus containing an embryo, the ordinary celloidin and paraffin- 

 methods were unsatisfactory. A combined celloidin-paraffin method gave 

 good results. The material was soaked in 4 p.c. celloidin and then 

 exposed to chloroform vapour. When the celloidin became solid, the 

 block was immersed in benzol and then imbedded in paraffin with a 

 melting-point of 58° C. 



Studying New Sporozoon in Rat-fever. J — From the blood and 

 lymphatic glands of two individuals suffering from rat-fever — rat-bite 

 disease — M. Ogata has obtained sporozoa, to which he has given the 

 name Sporozoa Muris. They appear to belong to the Neosporidia, 

 Inoculation of material from the ulcers, blood, or lymphatic glands of 

 the patient into rabbits and guinea-pigs causes the death of these 

 animals in from one to three months. From their blood, sporozoa in 

 various stages of development may be recovered. 



New Hot-water Funnel.§— Many of the present funnels for fil- 

 tering agar and other fluids at a high temperature, prove unsatisfactory 

 in use. V. Brudny describes an improved apparatus (fig. 35), free from 

 the disadvantages of the older types. It consists of a copper vessel in 

 the shape of an hour-glass. The lower truncated cone contains water, 

 maintained at a constant level by means of the small side-chamber 

 provided with supply and overflow tubes. The water is heated by 

 means of a Bunsen ring, which is fixed to one leg of the tripod stand 



* Biol. Bull., xvii. (1909) pp. 341-2. 



t Zeitschr. wiss. Zool., xciv. (1909) pp. 242-7. 



% Mitt. Med. Fakul. K.-Jap. Univ., viii. 3 (1909) pp. 287-318. 



§ Zeitschr. wiss. Mikrosk., xxvi. (1909) pp. 418-21. 



