402 ril. \PTEK XXXTT. 



water is poured on to them, they are again stoved for ten 

 minutes, rinsed with water, treated with 96 per cent, alcohol 

 till no more colour comes away, and passed through absolute 

 alcohol and xylol into xylol balsam. 



The method is also applicable to invertebrates, for which 

 other fixations than nitric acid are admissible, and the 

 impregnation with the molybdate may be done on the 

 sections instead of the uncut tissues. The results are not so 

 certain as for vertebrates. 



LUGARO (Riv. Pat. Nerv. Ment., Firenze, x, 1905, p. 269) modifies 

 this by fixing in nitric acid dissolved (to 1 per cent.) in aceton. 



DONAGGIO (Ann. Ncvrol. Napoli, 1904, p. 161) fixes pieces 

 not more than 5 mm. thick for five to six days in pyridin t 

 changed at least once, washes in water, and mordants for 

 twenty-four hours in ammonium molybdate 4 grms., water 100, 

 hydrochloric acid 4 drops. Wash, get into paraffin, trout 

 sections on slide for one minute with water, stain for tin-re 

 to thirty minutes in a 1 : 10,000 solution of fhionin, and 

 mount ; or, better, first treat again for fifteen to thirty 

 minutes with molybdate solution. 



JADERHOLM (Arch. mik. Anat., Ixvii, 1905, p. 108) finds that the 

 pyridin causes enormous shrinkage, and that the thionin agglutinates the 

 fibrils. 



PARAVICINI (Boll Mus. Z. Anat. Comp., Torino, xx, 1905, p. 514) 

 fixes and mordants in the dark, and differentiates after staining with 

 extremely weak hydrochloric acid. 



See also TOMASELLI, Zeit. wiss. Mik., xxiii, 1907, p. 422, and 

 MONTANARI, ibid., xxviii, 1911, p. 22, who describes observations which 

 seem to throw doubt on the objectivity of the network descried by 

 Donnggio. 



773. Neurofibrils, APATHY'S HeDmatein Method (Mittli. Zool. Hfal. 

 NcapeL, xii, 1897, p. 712). Material may }>e fixed with sublimate, liquid 

 of Zenker, picro-sulphuric acid, or any mixture that is not im in ic;il t<> 

 si Dining with alum harniatoxylin, and should be preserved in 9o p>r 

 cent, alcohol. Portions are stained for at least forty-eight hours in 1 lie 

 haematein solution 1 A, 259, and are then washed for up to twenty-four 

 hours in absolutely pure distilled water, preferably suspended therein. 

 Before the stain has become washed out of the neurofibrils, it is 

 therein by putting the preparations for three to five hours into 

 water, after which they are put back for not more than two hours into 

 di-tilled water, dehydrated :is r;ipidly as possible by hanging them up 



