No. 2.] THE DEVELOPMENT OF THE NEWT. 28 1 



tion of the strength recommended by O. Schultze ('87) I have 

 not reached his successful result with so long an immersion as 

 twenty-four hours. This may perhaps be due to the com- 

 paratively small size of Dianyctyhis eggs and their consequent 

 speedier penetration by the fluid. 



After an immersion of two hours in Flemming's mixture the 

 eggs are washed repeatedly with distilled water and 35 per 

 cent, alcohol, and then transferred to 50 per cent, alcohol, where 

 they remain for an hour, after which they are hardened in 70 

 per cent, alcohol for from twelve to eighteen hours. They are 

 finally passed successively through 95 per cent, alcohol, absolute 

 alcohol and xylol (or turpentine), not remaining above an hour 

 in each, and are imbedded in paraffine. After repeated trials 

 of Schultze's method of leaving the eggs for twenty-four hours 

 in each of the different grades of alcohol, I was obliged to 

 abandon it as eminently unsatisfactory for Diemyctyhis eggs. 

 A short stay in the alcohols afforded me much better results. 



I have stained in toto by putting the eggs, after their stay 

 in 70 per cent, alcohol, into borax carmine or alum cochineal 

 for twenty-four hours, and have in this way obtained excellent 

 preparations, particularly with the cochineal. For staining on 

 the slide I have used Mayer's method of fastening the sections 

 to the slide with albumen fixative. 



If the eggs are killed with hot water and then passed slowly 

 through rising grades of alcohol the results are quite as satis- 

 factory as those reached with Flemming's mixture. In some 

 respects, even, they surpass the latter, since shrinkage of the 

 germinal vesicle is less frequent with hot water than with any 

 other method. The eggs are dropped into water of about 

 80° C. for a few seconds, and then passed at once into weak 

 alcohol and slowly up to the higher grades. 



Perenyi's fluid and Kleinenberg's picro-sulphuric mixture do 

 not seem well adapted for use on the ovarian Q.^g. The latter, 

 in particular, badly distorts nuclear appearances. 



For study of the young living Q^'g I have relied chiefly upon 

 examination of perfectly fresh specimens in physiological salt 

 solution, though I have found both silver nitrate and methyl 

 green very helpful in determining certain points. 



