12 Bulletin Wisconsin Natural History Society. [Vol. 9, Nos. 1-2. 



to resemblance of animals to their environment, while mimicry refers 

 to the resemblance of one animal to another, the mimicked form being- 

 supposed to have some immunizing odor, taste, or defensive apparatus. 

 Thayer's theory may be briefly called a theory of "obliterative" colora- 

 tion. The lecturer showed a large number of slides in illustrating the 

 effectiveness of dorsal and ventral shadows, of stripes, bands, and 

 other patterns as obliterating the specimens in their proper environ- 

 ment. 



The lecture was discussed by Messrs. Burrill, Colles, Russel, and 

 Werner. 



Upon motion the meeting then adjourned. 



Milwaukee, March 9, 1911. 



Meeting of the combined sections. 



President Barth in the chair. 34 people present. 



Minutes of the last section meeting read and approved. 



Dr. Copeland reported on behalf of the committee in charge of 

 opposition to spring shooting that a hearing of the bill would take 

 place on Friday at which Mr. Ward and several other members of the 

 Society would attend. He also requested all members present to write 

 to the representatives of their district to oppose the bill. 



Mr. Senn stated that considerable illegal hunting of game and fish 

 was being done in the vicinity of Milwaukee, the proceeds being sold 

 chiefly in Indiana. 



Mr. Doerflinger suggested that it would be advisable to prove 

 conditions to the legislative committee by demonstration ; that at a 

 recent hearing of some bills presented by the Archaelogocical Society 

 for the preservation of Indian mounds it transpired that five members 

 of the committee had never seen an effigy mound. 



Mr. Alfred Senn then gave a talk on Trees and Tree-planting. Mr. 

 Senn deplored the existing individualism of property owners in tree 

 planting, stating that the bad results of indiscriminate planting, 

 overcrowding and neglect could be seen on all streets of the city. The 

 park idea is to preserve and build up the forests ; here the asymmetry 

 of the whole is to be preferred to the symmetry of the individual. For 

 street planting individual conditions are to be considered, such as the 

 ornamental qualities, the water supply, methods of planting, soil, etc. 

 The American elm, linden, white ash, and Norway maple are best 

 fitted for street planting, trees of not more than 18 inches circum- 



