Journal of Applied Microscopy. 



505 



mixture of acid fuchsin and methyl green or the safranin-gentian violet-orange 

 may be tried for nuclei. 



Xyliir/a. — Many forms, like Xy/ar/a, Ustiliua, Hypoxylon, and X'/z/iiiii/t/aria, 

 in their mature condition, are woody and so extremely brittle that it is almost 

 impossible to cut them. As good a plan as any seems to be to cut sections of 

 the stroma about one-eighth of an inch thick, soak them in equal parts of 

 glycerine and ninety-five per cent, alcohol, and then imbed them in celloidin in 

 the usual way. They might be cut without imbedding, but most of the asci and 

 spores would then be lost. 



The younger stages, showing the development of perithecia and asci, are 

 more interesting, and can be cut in paraffin and stained with ease. 



Pcziza odorata. — The Pezizas and related forms f)/^i'^'^ 



are fleshy and present but little difficulty in fixing, 

 cutting, or staining. They are abundant in moist 

 places on decaying wood or on the ground. The 

 apothecia have the form of little cups, which are some- 

 times black and sometimes flesh colored, but often 

 orange, red, or green. For the development of asco- 

 spores in the ascus Flemming's fluid (weaker solution), 

 followed by safranin-gentian violet-orange, has given 

 the best results with thin sections where the mitotic 

 figures are to be studied. Cyanin and erythrosin is 

 also to be recommended. For a general morphological 

 preparation, such as is shown in the figure, it is better 

 to stain in bulk in alum carmine or in Delafield's ha;ma- 

 toxylin, and then tease out the asci in glycerine or 

 balsam. Sections thick enough to show the entire 

 ascus are not usually as satisfactory as such teased 

 preparations. 



AECIDIOMYCETES. 



Fig. 31. Peziza odoraia. 

 rhree asci and many paraphyses. 

 ■ 245. Fixed in corrosive sub- 

 limate, stained in bulk in alum 

 cannine . Teased out and 

 mounted in balsam. 



The Aecidiomycetes comprise the rusts (I'redineai) 

 and the smuts (Ustilagineae). 



J^/nri/iia i^nimiiiis. — The common rusts of wheat 

 and oats are familiar to everyone. The uredospores 

 or summer spores, known as the red rust, and the 

 teleutospores (last spores) or winter spores, known as the black rust, are found 

 in unfortunate abundance, but the a-cidium stage on the barberry is not neces- 

 sary for the vigorous development of rust in the United States, and is seldom 

 found. Most teachers are obliged to depend upon botanical supply companies 

 for this material. There are, however, various a-cidia which are as good, or 

 even better, for morphological study. The aecidia growing on EupJiorbia »iaiii- 

 lata (spotted spurge), and on Arisu-ma triphylliim (Jack-in-the-pulpit) are much 

 easier to cut and seem easier to stain. Delafield's haematoxylin is good for both 

 secidia and spermagonia, especially after Flemming's fluid. It is rather difficult 

 to get good sections of uredospores and teleutospores, because the leaves of 



