INTERSTITIAL CELLS OF THE CHICKEN TESTIS. 



147 



A glance at Table I. will show the relation between the two 

 sets of means: taking the birds in the order nos. 666, 1271, 2323, 

 147, the tube size increases, and the space width decreases. 



TABLE I. 



ABSOLUTE MEASUREMENTS AND CELL COUNTS OF TESTICULAR ELEMENTS. 



MEAN VALUES. 



TABLE II. 



RELATIVE PROPORTIONS OF DIFFERENT CELL ELEMENTS. 



On examining the interstitial spaces in these four testes with 

 greater magnification, there appears to be what one w r ould 

 naturally expect, a greater number of cells in the larger triangles 

 and wider spaces. An accurate count of the cells shows this to 

 be the fact. The cells in twenty-five triangles of each of the 

 same four testes were counted. In order to count over com- 

 parable areas the cells were counted from the points of the tri- 

 angle along the spaces between each two tubules to about half way 

 to the next triangle (Fig. 3, A, B, C). The sections in the four 

 testes were of course cut the same thickness. A study of Table 

 I. shows that the number of cells varies with the width of spaces 

 and inversely as the size of the tubules, with one exception. That 

 is, arranged according to mean number of cells in spaces, the 

 birds stand in the order 666, 1271, 147, 2323, as contrasted with 

 666, 1271, 2323, 147, the order for tubule size. The exception 

 is in the reversal of 147 and 2323. The explanation of this lies 

 in the fact that the measurements are of the spaces between two 



