Permanent Aceto-Carmine Preparations

Abstract

Fasciations, irregular development of growing points in plants, occur in many plant families. Some of these can reproduce and all progeny show the same abnormality. Such cases are due to 1 or more specific genes for abnormal growth. Tumors in animals are also a form of unregulated growth. The injurious nature of unregulated growth in both plants and animals comes in later stages from a breaking down of cells. In plants there is no migration of abnormal cells, nor do fasciations and galls show malignant features of animal tumors. Many transmissible lethal factors in plants and animals stop development at an early stage when homozygous. If heterozygous for these genes the individual may be normal throughout its life, but if the protecting gene is lost abnormal development may occur. Deletions, non-disjunction, and other chromosomal aberrations may allow recessive genes to appear. Therefore chromosome irregularities might bring about chromosomal unbalance with resultant unregulated growth. Dibenzanthracene when injected into living tissue may bring about non-disjunction. Dibenzanthracene is an active principle of crude tar and crude tar has been shown to induce abnormal development.