Date of Defense

Summer 7-1974


Biological Sciences

First Advisor

Alan Russcher

Second Advisor

Michael Stoline


phytophthora infestans, P. infestans


Anencephaly and spina bifida cystica are two of the most common severe congenital malformations consistently observed in human populations. Both represent defects in the neural tube and share a significant number of similar epidemiological associations among them, occupational class, geography, sex ratio, maternal age, year and season of the year. In anencephaly most of the brain and upper skull never form usually resulting in death within a few hours of birth. Spina bifida cystica is a malformation of the spinal cord often causing paralysis, vulnerability to infection, and early death. In 1972, Dr. J.H. Renwick presented a controversial hypothesis which links epidemics of late blight of potato with epidemics of these two neural tube closure defects, which he refers to as ASB. A geographical correlation between high incidence rates for ASB and the distribution of potato blight epidemics throughout the world led to the investigations which produced a considerable array of evidence. In October of the same year, D.E. Poswillo et al. published the results of experiments performed on rats and marmosets. One group of each species were fed diets supplemented with blighted potato concentrate. None of the rats fed this preparation gave birth to any grossly abnormal offspring but of the eleven foetuses obtained from the sex female marmosets fed the potato extract, four showed gross cranial osseosus defects. Most researches have dismissed Renwick's hypothesis until Poswillo's experiments. This paper will try to reexamine Renwick's hypothesis with respect to new evidence published by other workers and the information obtained by this author working in Michigan.

Access Setting

Honors Thesis-Open Access