INTERNAL SECRETION OF TESTICLE 



119 



can arise from connective tissue cells. The same conclusion seems 

 to follow from new observations by Guilera and Kronfeld (1921). 

 Sometimes all transitions between the spindle-shaped nucleus of 

 the connective tissue cell to the spherical nucleus of the inter- 

 stitial cell can be observed ; but Rubaschkin suggested that the 

 connective tissue cells, from which after birth interstitial cells 



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Fig. 57B. — Development of interstitial tissue in guinea pig. 

 New-born animal (Prot. Nr. 103). 



arise, are also possibly elements originating from the generative 

 cords or the mesoderm. There might be present in the inter- 

 tubular tissue two different kinds of connective tissue cells: 

 those which primarily were mesenchymatous cells, and those 

 which primarily were epithelial and afterwards became con- 

 nective or mesenchymatous, but remained able to transform 

 themselves again into epithelioid interstitial cells. 



