have been >ecti< med and examined under die microscope to see if 

 cork formation or something similar prevented the advance of the 

 fungus in the tissues. So far nothing of the sort has been found, 

 but a much more thorough examination should be made to warrant 

 any definite statement. 



Summarizing, the results of the work so far indicate that the 

 greater resistance of the roots to the growth of the fungus is not 

 due to their greater content of tannic acid; it is not due to the 

 fact that roots are normally covered with soil and therefore have 

 not such a ready access to the air as the stems ; it is not due to the 

 fact that roots contain more moisture than stems; nor does it ap- 

 pear to be due to the formation of some special cicatricial tissue 

 by the root. We seem thus to be led up to the hypothesis that the 

 ' > ' ! " > ' utially a / > oplasuiii on, , bound up in some way 



with the nature of the living substance present in the cells of the 

 roots, although it is possible that one or more of the factors named 

 above is to some extent contributory. 



European Larch Canker 

 A considerable amount of infection of the European Larch and 

 other conifers by Dasyscyp/iu li'illk'onimii, the causal agent of the 

 European Larch Canker, was reported in 1927 by Dr. Perley 

 Spaulding and Mr. Paul V. Siggers of the Bureau of Plant In- 

 dustry to be present in several places in Massachusetts. At the 

 request of Dr. Haven Metcalf, Senior Pathologist in charge of the 

 Laboratory of Forest Pathology, I visited one of these infections 

 at Hamilton, Massachusetts, on August 2, and obtained a quantity 

 of the fungus. Inoculation experiments with this material are 

 now going forward, and a report will be submitted next year. 



Maple Wilt 

 At the request of several residents of Brooklyn I have examined 

 <lying maple trees, which in every case were the Norway maple 

 [.■leer platcuioitles). The trouble seems to be due to the "maple 

 wilt," caused by a fungus belonging to the genus /" crtieillin 111. 

 Further work on the habits of this fungus and its life-history ap- 

 pears to be much needed. 



