The search for quarks

Experimental and theoretical work on quarks is reviewed. The following topics are covered:- the quark model and its difficulties; fundamental particles with integral charges; quark searches with accelerators; search for polyquarks; quark searches in cosmic rays and the physico- chemical methods; and theoretical models for quark production. Experimental studies have so far led only to negative results, but with the latest accelerators, and particularly the intersecting proton-proton rings at CERN and the Batavia accelerator, there may be more promise. There may also be prospects for physico-chemical searches for quarks in various substances. It is quite possible, however, that quarks are quasi-particles of some kind that cannot exist in a free form. (97 refs).