GENERAL TECHNIQUES FOR CLASSES OF PLANTS 711 



Maxevai, (Bof. Cnz.. Ixxviii. 1924, p. 122) stains the spores with 

 carhol fuclisin, sulphuric acid and mcthylen bkio. He iinds 

 (Stain Tech., iv, 1929, p. 21) that treatment of the preparation 

 with tannic acid improves the staining of the ascus. 



Weidman and Freeman (J. Amer. Med. Assoc, Ixxxiii, 1924, 

 p. 1163) emulsify yeast cells upon the slide with a drop of India ink. 

 Kelley and Shoemaker (Bot. Gaz., Ixxxiii, 1927, p. 318) place 

 a drop of dilute (1 : 10) Mayer's albumen on a slide and add a small 

 drop of yeast culture and allow it to dry over a gentle heat. Stain 

 50 seconds in acid fuchsin, wash, dry and mount in balsam. 

 See also Henrici, J. Med. Res., xxx, 1914, p. 409. 

 Spore formation in yeasts can be secured by culturing on a 

 moistened gypsum block (see Will, Centrbl. Bakt. II, liii, 1920, 

 p. 471). 



1401. Myxomycetes. Broeksmit (Nederland. Kruidk. Arch., 

 1925, p. 134) states that plasmodia and unripe sporangia should 

 be gathered in small boxes lined with moist moss. The slightest 

 damage causes cessation of development or abnormal growth. 



Howard [Amer. J. Bot., xviii, 1931, p. 624) collects plasmodia 

 on plain agar in Petri dishes, and then repeatedly transfers them 

 to plates of plain agar to free them of contaminants. Later they 

 are grown on plates of rolled oat agar (30 grm. Quaker oats, 

 15 grm. agar, 1 litre of water) at 20° to 26° C. 



See also Ayers, J. Applied Microscojyy, i, 1898, p. 15. 

 Fix Plasmodia with Flemming fluids ; if a plasmodium can be 

 induced to creep on to a slide, it may be treated as a whole mount. 

 Imbed in paraffin if separable from substratum ; if inseparable 

 it is often better to imbed in celloidin. 



Gilbert (Amer. J. Bot., xxii, 1935, p. 52) fixes Ceratiomyxa in 

 an alcoholic variant of Bouin : 



Picric acid (saturated solution in 70 per 



cent, alcohol) . . . . . 75 c.c. 



Formalin (40 per cent.) . . . .25 c.c. 



Glacial acetic acid ..... 5 c.c. 

 He employs smears to study mitosis in the spores and a modifica- 

 tion of Cotner's method (§ 1399) for germinating spores and 

 s warmers. 



Stages in si)orangia and spore formation require rather thin 

 sections. Stain with Heidenhain's haematoxylin. 



Skupienski (Acta. Soc. Bot. Polonice, vi, 1929, p. 203) grew 

 Didymium under vital staining. It grew well in a mixture of 

 equal parts 1 : 5000 neutral red and methylen blue. The neutral 

 red stains the sporangia, the methylen blue the stipes. 



BRYOPHYTA 



1402. Mounts of whole plants and leaves, free-hand sections of 

 thalli and leaves, fruits, spores and elaters, peristomes, etc., are 



