7 
Harshbarger, J. C 0 &C. J. Dawe. Hematopoietic Neoplasms in Invertebrate 
and Poikilothermic Vertebrate Animals. In: Unifying Concepts of Leukemia , 
Bible haemat., No. 39, R. M. Dutcher & Chieco-Bianchi (ed.), pp, 1-25, 
Karger: Basel, (1973), 
Harshbarger, J, C 0 & R e M, Faust, Environmental Factors Internal to the 
Host That Affect the Success of Microbial Insecticides. Ann. N. Y. 
Acad. Sci., 217: 131-140. (1973). 
PAPERS IN PRESS 
Harshbarger, J. C. Radiation, Neoplasms, Carcinogenic Chemicals, and 
Insects. In: Insect Diseases . Vol. 2, G. E. Cantwell (ed.), Marcel 
Dekker: New York, (expected May 1974). 
Dawe, C. J. & J. C. Harshbarger. Neoplasms in Feral Fishes: Their 
Significance to Cancer Research. Symposium on Fish Pathology, 7-9 
August 1972, Armed Forces Institute of Pathology, Washington, D.C. 
(expected Spring 1974). 
HIGHLIGHTS 
Some significant discoveries pertaining to cold-blooded animal 
tumors during the last decade are listed below. Numerous examples of 
these and similar cases have been contributed to the Registry for which 
we are greatly appreciative. 
1. The initial discovery of the carcinogenicity of 
aflatoxins resulted from the study of hepatomas in 
hatchery rainbow trout. For brief history and 
tumor characteristics see Ashley, Laurence M. 
Liver Cell Carcinoma in Rainbow Trout. Amer. J. 
Pathol., 72: 345-348; 1973. 
2. The first fish neoplasms of central nervous system 
origin: (1) an olfactory neuroepithelioma in a bloater 
(RTLA 257); and (2) a retinoneuroblastoma in a croaker 
(RTLA 650). Since neuroepitheliomas can be induced in 
hamsters by a nitrosamine [Herrold, K. Cancer, 17 : 
114-121; 1964] perhaps nitrosamines are a significant 
environmental pollutant. 
3. A lamprey with a metastatic melanoma (RTLA 89) is the 
most primitive vertebrate in which a malignant type 
neoplasm has been found. 
4. A hematopoietic neoplasm in a sandbar shark (RTLA 523) 
is the only blood cell tumor in a Chondrichthyes. 
5. New evidence that a herpes virus causes the Luckd 
renal adenocarcinoma in leopard frogs. 
