438 Haploids and Autopolyploids 



life when unfortunately it was drowned. This animal, produced 

 by Baltzer and Fankhauser from an egg fragment, was dwarfed 

 and slightly anemic. Its reactions were very slow, it had diffi- 

 culty feeding, and its metamorphosis began much later than in 

 normal diploid animals. 



Fankhauser also raised a haploid individual of the Japanese 

 newt, Triturus pyrrhogaster, to the fifty-ninth day. This hap- 

 loid was produced by tying a loop of fine hair around the egg 

 shortly after the entrance of the sperm and tightening the loop 

 until the egg was cut into two parts. Usually one of the frag- 

 ments survives and consists of a nucleus with about half the 

 cytoplasm, thus preserving the nucleocytoplasmic ratio more 

 faithfully than by methods that merely inactivate one nucleus 

 of a fertilized egg and leave the full amount of cytoplasm. The 

 particular fragment that developed into this individual con- 

 tained the paternal set of chromosomes. It developed more 

 slowly than the normal diploid from the very beginning, and by 

 the ninth day just showed signs of the tail fin and of pigment 

 cells, although in the diploid a narrow fin surrounded the tail and 

 melanophores were scattered over the dorsal side and the flank 

 of the body. This retardation in growth became more and 

 more pronounced, and after a while the head and anterior part 

 of the trunk became distended with fluid in the tissues and body 

 cavity (edema). The head also became bent to the left and 

 ventral sides. The blood was anemic, and the animal became 

 weaker and slower to respond to stimuli. On the fifty-ninth day, 

 when it was obviously near death, the haploid and its diploid 

 controls were preserved. There is no doubt that this animal 

 was a haploid, for a piece of the tail tip was removed on the 

 nineteenth day and examined cytologically. Diploid and haploid 

 larvae are shown in Fig. 122. The dividing cells of haploids show 

 twelve chromosomes, the haploid number (Fig. 123). 



We have pointed out that the cells of the gametophyte genera- 

 tion of plants are haploid. Since the starch food (endosperm) 

 in the seeds of gymnosperms consists of a mass of gametophyte 

 cells, such tissue should be haploid. K. and H. J. Sax used this 

 tissue to study the number and morphology of the chromosomes 

 in a cytotaxonomic survey of the conifers. They find that the 

 root tips of conifers are not suitable material for a study of 

 chromosomes because the chromosomes are long with the arms 



