214 SUMMARY OF CURRENT RESEARCHES RELATING 10 



.Main with chrysoidin. The authors find that this method is very 

 satisfactory for the examination of fresh films. The plating methods 

 of Conradi and Troch, who recommend a tellurium medium, and of von 



1 >rigalski and Bierast, who use a bile-serum medium, do not give results 

 any better than those obtained on Loeffler's medium. Heymann's 

 enriching method has been found useless in the authors 1 hands. 



A. Hanau * has carried out observations upon the relative values 

 of Loeffler's serum, Rankin's potassium-sulphocyauide-neutral-red-gluoo-r 

 scrum, and Conradi and Troon's tellurium medium. His results show 

 that the newer media are in no way more reliable than Loeffler's serum. 



E. Seligmann f has examined 86 cultures from 42 patients, including 

 1 1 cases of diphtheria, 3 cases of ozaena, 8 convalescents, and 20 healthy 

 carriers, in the hope of finding certain criteria which would permit of 

 a sharp line being drawn between diphtheria bacilli and certain allied 

 forms. He finds that in the majority of cases the true diphtheria may 

 lie readily recognized, but there is no certain means of assigning some 

 doubtful forms to their proper place. 



(2) Preparing- Objects. 



Demonstrating Presence of Chondriosomes in Cartilage.J— L. 

 Torraca amputated the tails of a number of Tritons {Triton cristatas) 

 and fixed the material at various periods of regeneration. The fixative 

 used was Regaud's fluid (3 p.c. potassium bichromate 8 parts, formalin 



2 parts). The decalcifiers were 3 p.c. nitric acid and 1 p.c. chromic acid 

 or a mixture of equal parts of the two solutions. For staining, Heiden- 

 hain's iron-ha3matoxylin was exclusively employed. The technique was 

 as follows : — 1. Fixation in Regaud's fluid for 3 to 4 days ; the solution 

 being renewed on the least evidence of turbidity. 2" Decalcification 

 for 4 days in nitric acid or 5 to 6 days in chromic acid, or in the 

 mixture for 4 to 5 days. 3. Prolonged washing in running water. 4. 

 Mordanting in 3 p.c. bichromate of potassium" for 10 days, the fluid 

 being frequently renewed the while. 5. Washing in running water. 



6. Dehydration in alcohol, and embedding in paraffin. Sections : — 



7. Immersion for 24 hours in *2\ p.c. iron alum. 8. Staining in 1 p.c. 

 hematoxylin for 24 hours. 9. Washing in running water. 10. Differ- 

 entiation in the alum solution used for mordanting. 11. Washing in 

 running water until the preparation has a distinct blue tint. 12. Dehy- 

 dration ; balsam. 



Fixation of Soil Protozoal— K. R. Lewin and C. H. Martin refer 

 to a previous communication on this subject. || They have since found 

 that the following mixture gives better results than picric acid. 

 Saturated aqueous solution of mercuric chloride 1 part, methylated 

 spirit 1 part. The soil should be crumbled into this fluid, and mixing 

 is best accomplished by gently shaking the containing vessel, care being 

 taken to avoid making the clay component of the soil pass into suspen- 



* Centralbl. Bakt., lte Abt. Orig., lxxii. (1913) pp. 245-9. 

 t Centralbl. Bakt., lte Abt. Orig., lxxii. (1913) pp. 127-47. 

 % Anat. Anzeig.. xlv. (1914) pp. 459-74 (5 figs.). 

 § Nature, xcii. (1914) p. 632. 

 || See tbis Journal, 1913, p. 329. 



