and Laboratory Methods. 2499 



procedure was found to give good results, since it allows the paraffin to penetrate 

 only the seed coats and prevents the removal of the glycerine : 



1. Alcohol (98 per cent.), 30 to 60 minutes. 



2. Chloroform, 30 to 00 minutes. 



3. Chloroform with paraffin shavings, 60 to 90 minutes. 



4. Place in paraffin oven with melted paraffin 2 hours, changing the 

 paraffin two or three times. 



5. Make into a cake as usual. 



Complete sections of a thickness of 15 to 20 // can be cut from material 

 prepared by the above method. The comparatively large size of the starch 

 grains seriously interferes with obtaining good sections of the endosperm much 

 thinner than the above. The sections can be fixed to the slides with albumin 

 fixative as usual. After removing the paraffin it was found best to use alcoholic 

 stains. Kleinenberg's haematoxylin followed by alcoholic eosin and then followed 

 by absolute alcohol, xylol and xylol balsam makes a good combination. 

 Bureau of Chemistry, U. S. Department of Agriculture. BURTON J. HOWARD. 



A Useful Modification of the Life Box. 



Professor Osborn's article " On the Use of Compression in the Study of 

 Small Organisms," in the July number of the Journal, has suggested calling the 

 attention of biologists to a little device which I have employed for a number of 

 years, though I do not remember to have seen it described nor to have known of 

 its being used by others. It is a very simple modification of the life box (B. & 

 L No. 4785) which greatly increases its usefulness by enabling the observer to 

 surround the object under observation at any time with any desired reagent. It 

 consists merely in substituting in place of the ordinary cover-glass of the life box 

 a thin glass perforated by a small opening 

 near one margm (Fig. 1). As cover-glasses 



of the ordinary thicknesses are too fragile 



to stand being bored, I use a cover-glass -p^^ ^ 



from ^ to ^ mm. thick cut from a sheet 



of glass such as is made for mounting brain sections. This thicker glass is 

 not only strong enough to stand boring but has for this use several other ad- 

 vantages over the ordinary thin cover-glasses furnished with the life box. It is 

 not deflected from its position by pressure from below and the object beneath 

 is therefore held between two parallel /'/a//e surfaces, thereby obviating the 

 sliding of the object or the movement of the fluid about it from one part of the 

 box to another where the pressure is less or where surface tension is greater, as 

 happens frequently where a thinner flexible cover is used. Moreover, the 

 amount of pressure put upon the object is controlled directly by the observer 

 instead of depending on the elasticity of the cover-glass. A cover-glass of this 

 thickness allows the use of medium powers (I use Zeiss D) giving ample room 

 to focus as deep as necessary. The essential feature is, however, the opening 

 in the cover through which any fluid may be introduced beneath the glass 



