27 OTTO GLASER. 



sensitized paper. The diameters of such prints can be measured 

 by means of fine calipers and a vernier scale; while the exact 

 magnification is made known by a similar projection of the scale 

 of a stage micrometer. With the data thus secured the actual 

 diameters of the eggs can be easily computed. 1 



In the following table (Table I.) no attempt has been made at 

 the identification of individuals. The experiment is based on 

 twenty-two eggs photographed before fertilization and again 

 immediately after insemination. 



TABLE I. 



DIAMETERS OF EGGS. 

 Unfertilized. Fertilized. 



71.6*1 74-8 M 



75-4- 74-6 



76.3 72.9 



75-6. . 61.4 



72.6 69.9 



77-4 72.9 



78.4. 71-3 



76.9 74-0 



78.6 71.6 



65-9 74-3 



74-4 73-3 



75-4- ... 72.0 



75-4- 69.5 



75-4- 76.0 



7L9 72.3 



77-1 70.3 



76.3 73-i 



72.0 70.8 



75-6 69.5 



74-1... ..70.8 



71-2. . 77-5 



73-0 74-5 



Average: 74.6 Average: 72.1 



The result here a loss of 2.5 n is the same in sense as that 

 found in a comparable mass experiment reported in 1914. 



I next repeated the test on a smaller number of eggs whose 

 identity as individuals, before and after fertilization was guaran- 

 teed by their position along the threads. The results are assem- 

 bled in Table II. 



1 For help in making these projections under the most favorable conditions, 

 I am greatly indebted to Dr. Selig Hecht, who suggested the use of sensitized paper. 

 Before I made the final measurements Dr. Hecht codified the prints and until I 

 had his key to the system of labelling I could not by any means identify corre- 

 sponding silhouettes. The measurements of the eggs therefore were made under 

 circumstances which rendered the personal equation negligible. 



