1894.] MICROSCOPICAL JOURNAL. 45 



ing infection from the air. Tlie needle can new be moved 

 in all directions in the flask, or test tube. When the grip 

 is pressed downwards, the needle passes the opening of 

 the glass-tube, and it can then be " infected " or touch a 

 colony, sporangium, etc. ; after this the apparatus is taken 

 out, and replaced by the original stof)per which has been 

 in the meantime, flame sterilized. 



While the stopper of the flask is removed the cotton 

 wrapper of the needle should pass the flame. The latter 

 is then inserted in the new flask and the inoculation 

 made. After this the whole needle may remain in situ, 

 or it is taken out in the same way as it was taken out 

 of the first flask. The glass tube alone may remain in 

 this case, the needle itself is taken out and the stopper 

 Ce) is left as a filter. 



The transfers may be made in the Hansen box. The 

 needle can be used for many purposes, e. g. : secondary 

 introduction of medium (when the glass tube is left after 

 inoculation), its manipulation is easy, and the steriliza- 

 tion carried out without difficulty. A better form may be 

 constructed on the basis of the same idea. At any rate 

 this is the first attempt of abandoning such rude in- 

 struments as a glass rod or an unprotected piece of wire 

 as instruments for handling micro-organisms in the veg- 

 etable kingdom. 



Bacteriological Laboratory, Iowa State Board of Health, Dec. 24, 1898. 



Aeration of Tissues and Organs in Mikania and Other 

 Phanerogams. 



By W. W. ROW LEE, 

 ITHACA, N. Y. 



The author's investigations were undertaken in order to 

 ascertain if possible the function of certain aerotropic 

 roots and consisted of an examination of the details of 

 structure of these roots and especially those produced by 

 Mikania scandens. This plant belongs to the order 



