Artificial Production of Monstrosities in the Rabbit

Abstract

FOUR doe rabbits of unknown breeding were inseminated with the spermatozoa of one male suspended in a solution of 0·1 per cent colchicine in 0·9 per cent sodium chloride. Doe No. 8 gave birth to six normal young and one monster (Fig. 1). No. 13 gave birth to ten normal young; but on the following day was discovered devouring an eleventh, the normality or abnormality of which could not be determined. No. 14 gave birth to eight normal and one monster (Fig. 2). No. 16 gave birth to five normal and one with unclosed anterior fontanelle (Bregma) and with very small philtrum. This lived only five days. The experimental animals gave, therefore, twenty-nine normal young, two definite monsters, one defective young and one uncertain. In previous inseminations the same does had given fifty-nine young without abnormality. Since February, forty does of similar origin but also unknown heredity had produced 425 young from spermatozoa suspended in 0·9 per cent sodium chloride and no abnormalities had been observed.