284 JOURNAI. OF FORESTRY 



doubtless been taken by mice. The guards and forest laborers began 

 soon to find here and there dead mice and often sick ones. The disease 

 was manifested by thickly swollen belly and slow, feeble movements. 

 After infection by far the greater proportion of the mice naturally died 

 in their hiding places. 



In order to determine whether the agent had helped radically, some 

 14 days after the use of the typhus cultures in one district in which 

 bread crumbs had been laid out on 75 hectares and where the mice 

 had appeared especially numerous. I scattered wheat in many places. 

 The latter was never disturbed. On this account I consider justified 

 the assumption, with which the district guards agree, that the effect of 

 the agent has been very good and thorough, and I am convinced that 

 without its use almost none of the beech seed would have remained. 

 Upon the basis of my experience I might recommend in further in- 

 stances of use that the cultures be, above all, laid out timely, i.e., at the 

 beginning of winter. Indeed, it is a well-known phenomenon that beech 

 seed years as a rule coincide with mouse years, and on this account 

 forest guards should, in my opinion, in the fall of the year, after re- 

 moval of the leaves on numerous observation places in the sowing 

 areas, be urged to ascertain the average number of mouse holes per 

 square meters in order thereby to furnish a safe standard for the 

 extent of the appearance of the pest. With a very heavy seed crop, 

 naturally, less consideration need be paid to the destruction than with 

 a very sparse seed crop, which (contrary to the common principle that 

 "quarter-mast" is not to be used) is in many cases indispensible for 

 the regeneration, particularly in smaller communal forests and regions 

 with infrequent beech seed crops. 



In conclusion it may still be noted that the use of typhus cultures 

 has also taken place with excellent success here, for the destruction of 

 mice in the forest nursery. The contents of a few tubes, laid around 

 for short periods, was sufficient to keep a nursery completely mouse 

 free. 



