PLATE 1 



EXPLANATION OF FIGURES 



1 1, Mus on earth, leaves and lime; 2, Microtus and Blarina on moist earth; 

 3, Mus and Microtus on dry earth, leaves, and twigs. 



2 1, Microtus and Blarina on moist earth; 2, the same on lime. 



3 1, Microtus and Mus on ashes; 2, the same on moist earth, leaves, bark, 

 etc. Peromyscus placed venter uppermost, 1, on ashes, 2, on moist earth. 



4 1, Mus on dry earth mixed with lime and leaves; ^, Mus on moist earth. 

 Both placed venter uppermost. 



5 1, Mus on earth; 2, Mus on leaves of cotton wood (Populus) and styles and 

 staminate flowers of corn (Zea). Placed venter uppermost. 



6 1, Microtus on earth mixed with leaves, etc; 2, Microtus on lime. 



7 1, Mus on earth, leaves, and lime; 2, Mus on snow. 



8 1, Mus on ashes, venter uppermost; 2, Mus on lime; 3, Mus on gypsum. 



9 /, Microtus on moist earth; 2, Microtus on ashes. Both placed venter upper- 

 most. 



10 1, Mus on earth; 2, Mus on leaves of corn (Zea). Both placed venter upper- 

 most. 



11 1, Microtus on mixed earth, lime, and leaves; 2, Mus on mixed clay, leaves 

 and earth. 



12 1, Rana cantabrigensis on sand; 2, the same on earth. 



13 1, Mus on moist earth; 2, Mus on dead leaves; 3, Mus on wet clay, leaves 

 and straw. 



14 1, Mus on moist earth; 2, Mus on clay. Both placed venter uppermost. 



15 1, Mus on clay; 2, Mus on dry earth with scattered bits of leaves and 

 twigs. 



16 1, Mus and Microtus on ashes; 2, the same on moist earth, leaves, bark, 

 etc. 



17 1, Rana pipiens on sand; 2, Rana pipiens on grass. 



18 Rana pipiens on moist earth. 



19 Epimys on moist earth, venter uppermost. 



20 Epimys on ashes, venter uppermost. 



21 Epimys on mixed ashes, gypsum, earth and clay. Venter uppermost. 



22 Epimys on gypsum. 



23 Epimys on leaves, sticks, and straws mixed with clay. 



ABBREVIATIONS 



b, Blarina brevicauda nii, Microtus drummondi 



TO, Mus musculus p, Peromyscus bairdi 



Except as otherwise noted, the animals are in every case placed dorsum upper- 

 most. 



dl For an explanation of the methods employed in photography, see pp. 458-9 

 in the text. 



Figs. 1, 3, 4, and 9—1:9; 2—1:10; 5, 14, 15, and 17—1:8.5; 6—1:9.5; 8—1:7.5; 

 7, 11, 13, 16, and 18—1:8; 10—1:6.5; 12—1:7.5; 19 to 23—1:20; 28, 29, 31, 32, 55, 

 57—8:7; 48—6:7; 49, 51, 53—4.3; all others 1:1.5. 



502 



