IOWA ACADEMY OF SCIENCES. 12S 



not hesitate to make use of such processes for the adultera- 

 tion of butter. 



Almost any person using butter can easily be imposed upon 

 with such a product. These facts naturally cause one to 

 realize the possibilities of adulteration of butter in other 

 ways besides the addition of fats which are not butter fats, 

 and force us to the conclusion that our states should have laws 

 preventing the excessive amount of water in butter, as well as 

 adulteration by other means. 



NATIVE CRAB APPLES AND THEIR CULTIVATED 



VARIETIES. 



JOHN CRAIG AND H. HAROLD HUME. 



Indigenous to North America there are several species of 

 Pyrus belong to the Mains or apple group. Sargent, in his 

 Silva of North America, gives three species and one variety. 

 These are P. rivularis Doug., found west of the Rocky moun- 

 tains from northern California to Alaska; P. angustifolia Ait., 

 ranging from Pennsylvania to Tennessee and Florida; P. 

 coronaria L., in the region from New York to Michigan, south- 

 ward and westward to Missouri and Kansas; P. coronaria var. 

 lowensis, Wood, confined to the prairie states. In the Ameri- 

 can Garden, XII, 473, 1891, Professor Bailey raised var. lowensis 

 to specific rank, basing his decision upon fruit and leaf char- 

 acteristics, and in the same article described the Soulard crab 

 as a species. Later, however, he expressed it as his opinion 

 that the latter is a hybrid, so according to the present classifi- 

 cation, we have the four species, P. rivularis, P. angusti- 

 folia, P. coronaria, and P. lowensis. 



These four are generally looked upon as good species. 

 Centuries of in and in-breeding and adaptation to environments 

 have for the most part stamped their work upon their forms 

 and characteristics, though on the borders of their geograph- 

 ical limits they doubtless bland into one another. Some 

 writers have wondered that hybrids have not more commonly 

 occurred between these species and the common apple. There 

 are many things to be considered; the time of flowering, the 

 adaptability of sexual elements, etc., and again, it is a well 

 known fact in the breeding of animals an old and fixed 



