242 SUMMARY OF CURRENT RESEARCHES RELATING TO 



refraction of the transparent setae, that in order to study them advan- 

 tageously it was found advisable to kill the specimens by compressing 

 them under the cover-glass, and then at once to make camera-lucida 

 drawings of the setae in the dorsal and ventral bundles. 



Impression Preparations.* — G. Sticker has found that excellent 

 preparations of solid organs can be obtained in the following way. 

 The surface of the tissue or organ is cut smooth with a sharp knife and 

 then a slide is gently pressed down. In this way one or more impres- 

 sions can be taken on the stime shde. As a matter of practice the author 

 advises beginning with lymphatic gland or spleen. The method is not 

 very successful with blood and exudations, or with tough connective 

 tissues. If an organ be very juicy it may be allowed to dry in the air, 

 or treated for a' short time with alcohol, formalin, etc. The impression 

 films are best stained by May and Griinwald'sf method, or with 

 methylen-blue or carbol-fuchsin. 



The author claims that this procedure has many advantages over 

 sections. 



Studying the Paraganglia of Birds. J — W. Kose used the following 

 materials : paraganglion caroticum, paraganglion suprarenale, and sym- 

 pathetic ganglia. Eleven different fixatives were tried, Miiller-formalin 

 giving the best results. The staining reactions of the chromaffin cells, 

 the plasma pigment, the connective tissue, the elastic fibres, were studied 

 by numerous and appropriate methods. Supravital staining with 

 methylen-blue (^ p.c.) for 1-24 hours, followed by picrate of ammonium 

 for ^-24 hours, was found to show the nerve-fibres very successfully. 

 Digestion experiments were carried out with pancreatin-glycerin and 

 pepsin-glycerin, the former diluted with * 3 p.c. soda, the latter with 

 O*:^) p.c. HCl. The sections were defatted by means of benzin, and 

 afterwards kept in the digesting fluid at 37°-4U° for 24-4S hours. 



Technique of Blood Examination in Tropics. §^ — Sheffield Neave 

 kept his slides in pure lysol, and after a time washed and placed them in 

 boxes ready for use. Any dulling of the surface improved the film. 

 Films from Mammals were easily secured, but with the blood of birds, 

 reptiles and fishes, there was considerable difficulty in obtaining good 

 preparations. The films were treated with Leishman's stain, the slides 

 being placed film downwards in the trough in order to avoid surface 

 deposit. If any deposit occurred it was easily removed by leaving the 

 slide in xylol for |-2 hours, and then wiping gently with a silk hand- 

 kerchief, and rinsing again in the trough. The obtaining of useful 

 citrated samples of blood for the purpose of detecting development of 

 parasites was attended with difficulties, one of which is that citrate 

 makes the blood of birds and fishes glutinous and hence more dilficult 

 to manipulate, both in the centrifuge and in making films. The system 

 of making thick films and de-haemoglobinising to detect extra-corpus- 



* Centralbl. Bakt., Ite Abt. Orig., xliii. (1907) pp. 206-8. 

 t See this Journal, 1906, pp. 627-8. 



J Archiv Mikr. Anat. u. Entwickl., Ixix. (1907) pp. 563-663 (3 pis.). 

 § Second Report Wellcome Research Lab., Khartoum, 1906, 255 pp., 21 pis. and 

 106 figs. 



