SOMMAIRE : Ch. 1 Introduction 1 Ch. 2 Spontaneous Tumors 5 Ch. 3 Chemically Induced Tumors 31 Sect. 1 Cytoxan 33 Sect. 2 L-PAM (Melphalan) 37 Sect. 3 Procarbazin (MIH) 51 Sect. 4 Methylnitrosourea (MNU) 55 Sect. 5 Imuran 61 Sect. 6 Adriamycin 65 Sect. 7 Aflatoxin B[subscript 1] (AFB[subscript 1)] 69 Sect. 8 Diethylnitrosamine (DENA) 87 Sect. 9 Saccharin 113 Sect. 10 Arsenic 119 Sect. 11 Sterigmatocystin (SMT) 125 Sect. 12 IQ 131 Sect. 13 Urethane 145