THE GONADS OF THE FOWL 105 



3. The hemocytoblasts become granulocytoblasts ( = myelo- 

 blasts) after deposition of acidophile granules in their cytoplasm. 

 While in this stage they preserve the round shape in their nuclei 

 and may increase in numbers by mitosis. 



4. The granulocytoblasts eventually become eosinophile leu- 

 cocytes after constriction of their nuclei, which usually break 

 into two or more portions. The eosinophile leucocytes or granu- 

 locytes (Danchakoff) thus formed are elements doomed to dis- 

 appear engulfed by the cytoplasm of special phagocytic cells and 

 are also phagocytized by the endothelium. They may degener- 

 ate in situ, setting free the granules contained in their cytoplasm. 



5. The small lymphocytes, produced in the mesenchyme and 

 lymphatic nodules, are cells endowed with several cell potential- 

 ities. Besides becoming granular leucocytes of smaller size, they 

 give rise to large wandering cells which agree in their characteris- 

 tics with cells hitherto regarded as interstitial. Such cells may 

 store fat in their cytoplasm, thus losing their wandering proper- 

 ties. Since they may be entirely absent in some testes it does 

 not seem probable that they possess an endocrine function. 

 Though they may perhaps have some bearing on the appearance 

 of the secondary sexual characters in the young bird, they are 

 not necessary for the maintenance of such characters in the adult. 



6. The granule-laden interstitial cells described in the ovary 

 and testis by Boring and Pearl are granulocytoblasts ( = mye- 

 loblasts) produced as the result of the hematopoietic capacity 

 of the connective tissue. The production of such cells may be 

 very active under certain unknown physiological conditions, lead- 

 ing to a myeloid metaplasis of the connective tissue. 



7. The mature cock-feathered male lacks a specific interstitial 

 tissue influencing the secondary sexual characters. 



