The chromosome complex of the pig was investigated in male germ cells with two distinct breeds as material.
The chromosome number was found to be 40 in diploid and 20 in haploid. After the morphological analysis of the chromosomes, the evidonce pointed out shows that there is present no visible difference in the chromosomes between the breeds under investigation, either in the number of chromosomes or in the other external morphological characters. The low count of the chromosome number given by some previous authors is accounted for as a result of faulty preservation of the material.
It was found that the pig possesses the sex chromosomes of the typical. XY-type. The X element is represented by one of the larger chromosomes of rod-type, while the Y is a very small one which is comparable to the smallest autosomes in size.