250 THREE WESTERN BIRD GROUPS 



cast had been taken from the mould (the species of Opuntia 

 in wax, the others in plaster) they were colored from our 

 field studies of growing plants, and the spines were then re- 

 placedan almost endless task. 



Doubtless the best comment on the measure of success 

 attained in this work was furnished by a member of the 

 Botanical Laboratory staff who, after inspecting the finish- 

 ed group with the utmost care, declared his inability to de- 

 termine whether the plants were real or not ! 



Barrel Cactus 



