and Laboratory Methods. 2161 



tions cut off in scrolls. The scrolls are placed on a small drop of distilled water, 

 previously placed in the center of a well-cleansed glass slip. Here they usually 

 flatten out of their own accord, if the knife has been well sharpened and the 

 paraflfine is of the proper hardness. Especially obstreperous scrolls are flat- 

 tened by holding sufficiently high above a small flame not to allow the paraflfine 

 to melt. Usually, however, in the case under consideration, it is found more 

 desirable to cut a few extra sections and place them on the drop of water, 

 selecting for study only the ones that unroll of their own accord. 



The slide is then set aside under a loosely placed bell-jar, and the water 

 allowed to evaporate spontaneously. After it appears dry the slide is held over 

 a low flame until the paraffine just begins to melt. It may then be stored away 

 and kept indefinitely in that condition. 



The remainder of the process is similar to the one usually followed, the 

 paraffine being dissolved off with xylol, the slide carried through alcohol and 

 even washed under a stream of water without disturbing the sections, which are 

 held to the glass by simple adhesion, I have within the past two years thus 

 handled hundreds of leaf sections of several species and do not recall a single 

 instance where a properly cut and flattened section came off in the usual process 

 of staining and mounting. 



The process here outlined is a slight modification of Nussbaum's (Anat. 

 Anz., Bd. XII, 1896, pp. 52-54; ref. in Zeits. wiss. Mikr., XIII, p. 309). I am 

 not prepared to state from experience how far it is applicable to the treatment 

 of other plant tissues. 



Of all the stains I have tried for the cuticle, Sudan III, proposed by Bus- 

 calioni (Sep. from Malpighia, XII, p. 1-20), has proved most satisfactory for 

 permanent mounts. A double stain with the latter and Delafield's haematoxylin 

 succeeds very well for photomicrographic purposes. 



My practice is to treat sections with alcoholic solution of Sudan III until 

 the cuticle has taken on an intense coloration, pass rapidly through alcohol to 

 water, thence into dilute haematoxylin, where they remain until the cellulose 

 walls assume the desired intensity of color. The sections must be finally en- 

 closed in glycerine or glycerine jelly. Samuel M. Bain. 

 University of Tennessee. 



Arthur L. Dean, in an article on Experimental Studies on Inulase, gives 

 the following formula for the medium on which pure stock cultures of Aspergillus 

 niger and Penicillium glaucum were kept : 



Agar-agar, 10 gms.; NaCl, 2.5 gms.; peptone (Griibler's), 2.5 gms.; beef ex- 

 tract, 1 gm.; inulin (air dry), 5 gms.; water, 500 c. c. The inulin used was pre- 

 pared from Dahlia variabilis by alcoholic precipitation. — Bot. Gaz. XXXV, 1. 



