402 SUMMARY OF CURRENT RESEARCHES RELATING TO 



better result is exhibited by a more complicated procedure. The sec- 

 tions were hot-stained with 1 per cent. bleu-de-Lyon, then washed, and 

 differentiated with a solution made up of sp. vini 3, aceton 3, distilled 

 water 3. and anilin 1. After washing with sp. vini, the sections were 

 stained with carbol-fuchsin, and then differentiated with 1 per cent. 

 HCl-alcohol. The sections, having been washed in water, were con- 

 trast-stained with an aqueous slightly acid solution of Bismarck-brown, 

 then dehydrated in alcohol 5 cleared in xylol, and mounted in balsam. 



Study of Central Nervous System.* — Dr. G. C. van Walsem gives 

 a systematic and critical account of the technical methods employed in 

 investigating the central nervous system, discussing at length macro- 

 scopic preparations and drawings, microtome sections, fixing, staining, 

 and so on. 



Demonstrating Hsematozoa of Padda oryzivora.f — M. A. Laveran 

 has been able to demonstrate by a special staining method a hitherto 

 unobserved phase in the development of the endoglobular hsematozoa of 

 Padda oryzivora. Fresh rubbings of spleen pulp are fixed in a saturated 

 aqueous solution of picric acid. After having been washed in water, the 

 films are stained with a mixture of eosin and Borrel's blue.| After an 

 immersion of 15-18 hours, the preparations are washed in distilled water, 

 and then treated with 5 per cent, tannin solution for some minutes. 

 They are then dehydrated, and mounted in balsam. The newly observed 

 parasites are spherical or oval bodies, 2-3 //, in diameter, and are found 

 free in the plasma or within cells. They appear to be present in great 

 abundance, while the numbers of the pigmented parasites are not in- 

 creased. They are not evident in fresh blood nor after ordinary staining 

 methods. 



Demonstrating Canaliculi of Bone.§ — Dr. W. Colquhoun arranged 

 glass tubing in lengths of about 12 feet up the wall of the laboratory. 

 To the bottom of each of these tubes a bone (e.g. tibia of sheep) was 

 fastened by means of rubber tubing and a rubber cork, after an end had 

 been sawn off and the medullary cavity cleaned out. The periosteum 

 was also stripped off, and any opening on the outside of the bone plugged 

 with wooden pegs. The tubes were then filled with some staining solu- 

 tion containing a little antiseptic, and the bone left exposed to the warm 

 air of the room, so that, as it lost moisture from the outside, the stain 

 would be sucked in by the natural channels. After about a month the 

 nuclei of the bone and the lining membrane of the canals were found 

 stained. The sections were made by grinding after permeation with 

 balsam. 



By the foregoing procedure the cnnaliculi were but faintly stained, 

 and this defect was remedied by using first a penetrating fixative (such 

 as 3 per cent, bichromate of potassium with or without 0*25 per cent. 

 osmic acid) and following this up with a fluid (such as 1 per cent, 

 nitrate of silver), which would form a precipitate by chemical combina- 

 tion with the first. After the first fluid had been allowed to act for a 



* Verb. K. Akad. Wetenschap. Amsterdam, vii. (1S99) pp. 1-184 (8 pis. and 

 SO figs.). t O.K. Soc. de Biol., Hi. (1900) pp. 19-22. 



X Cf. this Journal, ante, p. 264. 

 § Journ. Anat. Physiol., xxxiv. (1899) pp. 84-9. 



