The second type is the agricultural college and experiment station libraries combined into a single agricultural library and kept separate from the university library, as at Wisconsin. This type may be considered as belonging to the departmental type of library. Other states which have adopted this plan are California, Iowa, Minnesota, Missouri, Nebraska and Virginia. In the third type the collections of agricultural literature including the experiment station collections, are consolidated with the college or university collections and administered as one unit. Examples of this type are the libraries of the University of Illinois, the Oregon agricultural college and the Kansas agricultural college. Under certain conditions the advantages of one type may far outweigh the disadvantages and leave little doubt that this is the best for the particular institution concerned. In the library of the first type,--namely, the experiment station library kept separate from the college library but under its control, the collections are composed principally of the following classes of literature: 1. As complete a collection as can be had of publications (a) of the U. S. Department of agriculture; (b) of state experiment stations in the United States; (c) of agricultural, horticultural, dairy and live stock and kindred societies; (d) the publications of departments of agriculture, of agricultural schools and societies in foreign countries, all of which literature may be designated as the "official agricultural literature." (2) Files, at least current ones, of the leading agricultural periodicals of the United States, together with the best of those published in the interest of each of the special branches of agriculture,--live stock, dairying, horticulture, etc. (3) A collection of reference works both general and agricultural, as well as standard works on agriculture and its various branches and allied sciences. Few if any of the separate experiment station libraries can be said to have notably complete collections, aside from the "official agricultural literature." Scientific books and periodicals are expensive and most of the agricultural colleges have not felt able to duplicate expensive sets of periodicals and scientific reference works. Therefore, since the college needs such works as well as the stations, the result has been in most cases that they have been filed in the college or university library and the station collections have been limited principally to the "official agricultural literature" described above.