322 GOLGI BODIES, ETC. 



726. Other Methods and Modifications. Besta {Anat. Anz., xxxvi, 

 1910, p. 477) fixes for two days in 20 parts of formol with 2 of acetic 

 aldehyde and 80 of water, washes for twenty-four hours in distilled 

 water changed seven or eight times, and puts for two days in 4 per cent, 

 solution of ammonium molybdate, makes paraffin sections, stains in a 

 1 : 1000 solution of thionin, differentiates in 3 parts of creosote to 1 of 

 absolute alcohol, and passes through pure creosote and xylol into 

 neutral balsam. Recommended for Purkinje cells and spinal ganolia 

 of young animals. '^ 



SucHANOw {Neurol. Centrbl., xxi, 1902, p. 777) has obtained good 

 results by the use of Golgi-Veratti mixture, keeping pieces of spinal 

 cord and spinal ganglia for twenty to thirty days in the mixture and for 

 two to three days in the rejuvenating fluid. 



Legendre (Anat. Anz., xxxvi, 1910, p. 209) omits the toning and 

 bleaching by Golgi's arsenious acid method, and imbeds in paraffin. 



Similarly Collin et Lucien, Bibliogr. Anat. Supp., 1909, p. 238. 



Savagnone {Pathologica, i, 1909) silvers pieces fixed in Golgi's arse- 

 nious acid mixture with 30 c.c. of tachiol (10 per cent, silver fluoride) in 

 100 of water. 



Carleton {Journ. R. Micr. Soc, 1919, p. 321) reduces pieces treated 

 according to Cajal's uranium nitrate method for only two hours in the 

 usual hydroquinone mixture. 



Penfield (Brain, xliii, 1920) has successfully employed Cajal's 

 uranium nitrate method for his experimental investigations on the 

 alterations of Golgi's apparatus in nerve cells of spinal cord and spinal 

 ganglia of young cats. He adds 20 c.c. formalin (instead of 15) to Cajal's 

 fixing fluid and as much as 15 gmi. of sodium sulphite to the hydro- 

 quinone-formalin solution. He finds it imperative to dehydrate pieces 

 very quickly before imbedding them in paraffin. In order to obtain per- 

 fect fixation of the spinal cord he sometimes performs a laminectomy in 

 the lower lumbar region of the anaesthetised animal, passes a needle 

 in the subarachnoid space, and allows the fixative to flow in " under a 

 gravity pressure of 75 cm." The heart stops about a minute after the 

 beginning of the injection, which is continued for twenty hours. At 

 the end of this time the cord is removed, pieces cut and dropped directly 

 into the silver bath. 



727. Counterstaining. Penfield finds it particularly useful to 

 immerse untoned sections into a diluted solution of Unna's 

 polychrome-methylen blue for one to four hours, this being 

 followed by passage through alcohols of increasing strength and 

 differentiation in absolute alcohol. 



By this method, also Holmgren's trophospongium is sometimes 

 stained. But for the study of the relationship between the latter and 

 Golgi's apparatus, Penfield (in liUeris) prefers to make drawings of the 

 apparatus from certain selected cells, subsequently removing the 

 coverslip and bringing the slides through graded alcohols into 5 per 

 cent, iron alum for twelve to twenty-four hours. This removes all 

 silver from the cells as well as the counterstain, and at the same time 

 mordants the tissues for further staining by Heidenhain's iron hjema- 

 toxylin method. If the proper amount of differentiation has been 

 secured of the particular cells already drawn, the trophospongium will 

 be found stained with great detail. 



Counterstaining may also be done in borax carmine (three to 

 twenty-four hours) 0-5 neutral red or toluidin blue in water 



