THE DIPLOID CHROMOSOME COMPLEXES OF THE PIG 187 



be added to 50 cm. to bring it up to a magnification corre- 

 sponding to that used in the present work — 50 + 16 = 66 cm. 



The total average length of the spermatogonia! chromosomes 

 in my material — 136.9 cm. 



The total average length of the dipoid chromosomes in 

 Wodsedalek's material — 66.0 cm. 



The length of the latter chromosomes is 48 per cent that of 

 the upper lot, or very nearly one half — 66 cm. X 2 = 132 cm. 

 This is so near the average length of the spermatogonia! chromo- 

 somes found in my work as to be practically identical. In the 

 same way the widths may be determined. I was hampered 

 again by being unable from the figures to determine certainly 

 the limits of the chromosomes, but I think that any error that 

 may have been introduced has been largely checked by averaging 

 the results. 



Average chromosome width — 12 mm.; + I magnification — 16 

 mm. Average chromosome width in my material — 7 mm. 



The first set is a trifle more than double the width of the 

 latter, not a sufficiently great difference, however, to be signifi- 

 cant, considering the chances of error. Text figure 5 illustrates 

 the above results graphically. At the right is the figure of the 

 spermatogonia! chromosomes in Wodsedalek's paper, and a 

 column drawn to scale from the above calculations illustrating 

 the average total length and average width of the chromosomes. 

 To the left are corresponding figures representing the present 

 work. This column is obviously a little over twice as high 

 and one half as wide as the column to the right. The area of 

 the left hand column (as reproduced) is 468.5 square mm.; 

 of the right hand column, 441 square mm. It is safe to con- 

 clude therefore that both Wodsedalek and myself have been 

 dealing with the same amount of chromatin, and the difference 

 lies wholly in the difference of the preservation of the chromo- 

 somes ; those in the former study being clumped and undecipher- 

 able, while those reported here are well separated. 



Though I have little, direct proof to offer at present, I am in- 

 clined to believe that other features of the chromosome history 

 reported in the earlier paper, particularly^ as regards the num- 



