524 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Walter Bagshaw, was shown by Mr. C. Lees dirties, F.R.M.S. Dr. 



Spitta referred to the great variability of Navicula smithii. Mr. F. 

 Martin Duncan, F.R.P.S., gave a lecture on " The Romance of Forest 

 Life," with lantern illustrations. 



Koch, L. — Die miki-oskopische Analyse des Drogenpulver. Ein Atlas fur Apotheker, 

 Drogisten, und Studierende der Pharmazie. 



Berlin : Gebr. Borntrager, 1908. Vierter Band (Schlussband) : Die 

 Samen und Friichte (14 lith. Taf. u. 16 Holzschritten). 



B. Technique.* 

 CI) Collecting- Objects, including' Culture Processes. 



Cultivation of Spirochaeta Duttoni.t — C. M. Duval and J. L. 

 Todd have successfully cultivated this organism on a medium which is 

 prepared as follows : — " The yolks of two fresh hen's eggs are carefully 

 separated from the whites under aseptic precautions and dropped into 

 a 200 c.cm. Erlenmeyer flask, to which has been previously added 

 100 c.cm. of a sterile mouse decoction, made by boiling the skinned 

 bodies of six mice in 500 c.cm. of water. This mixture is thoroughly 

 shaken until it is homogeneous, when 5 c.cm. of defibrinated sterile 

 mouse blood is added to it. The flask is now sealed, to prevent drying 

 of the medium, and placed at 37° C. from six to eight weeks until the 

 mixture undergoes partial digestion. The semi-fluid mass first becomes 

 solidified and finally, through autolytic action, is broken down to a 

 mush-like, grumous mass. In our experience this partial auto-digestion 

 of the medium seems essential to the multiplication of the Spirochaetse. 

 If the egg mixture is coagulated at higher temperatures it seems to be 

 no longer suitable for the growth of the parasites." The authors 

 formulate the following conclusions as the result of their experiments : — 

 (1) That Spirochmta duttoni can be maintained virulent for white mice 

 for forty days ; (2) that it will multiply and can be successfully 

 transferred in artificial media. 



Examining Living Leucocytes in vitro.J — C. Ponder describes a 

 method whereby he obtains perfectly clean preparations of a great 

 quantity of leucocytes obtained direct from any blood, the leucocytes 

 being kept alive for quite a long time. The necessary apparatus is to 

 be found in all pathological and physiological laboratories ; the only 

 other unusual material is modelling clay or " plasticine." 



The essential point is the preparation of a blood-chamber whereby 

 the white cells are allowed to escape from the clot and adhere to the 

 surface of a slide or coverslip, the clot being afterwards removed. To 

 make this chamber a morsel of plasticine, half the size of a pea, is 

 rolled out until it is as thin as the lead of a pencil and about an inch 

 and half long ; this is then taken and gently fixed on a clean slide, so 



* This subdivision contains (1) Collecting Objects, including Culture Pro- 

 cesses ; (2) Preparing Objects ; (3) Cutting, including Imbedding and Microtomes ; 

 (4) Staining and Injecting ; (5) Mounting, including slides, preservative fluids, etc. ; 

 (6) Miscellaneous. t Lancet, 1909, i. pp. 834-5. 



% Proc. Cambridge Phil. Soc, xv. (1909) pp. 30-3 (2 figs.). 



