342 SUMMARY OF CURRENT RESEARCHES RELATING TO 



referred to has its parallel in the well-established fact that if a colt is 

 castrated when shedding its winter coat, the shedding is for a time 

 arrested and then proceeds only very slowly. When wild ducks assume 

 the drake plumage the spurious males undergo the seasonal eclipse, but 

 this is somewhat incomplete and aberrant. 



Removal of the testes during the eclipse does not produce any 

 constant appreciable effect upon the next passage of the bird into winter 

 plumage. It would appear that the seasonal change of plumage in the 

 mallard is not connected with the spermatogenic function of the testicle, 

 but the influence of a hormone was not excluded since the castration 

 never prevented some re-growth of testicular tissue. 



b. Histology. 



Connective-tissue of Umbilical Cord of Torpedo.* — E. Laguesse 

 has studied the minute structure of the stalk of the yolk-sac in Torpedo 

 ocellata, which consists internally of a vitelline pedicle and externally of 

 a prolongation of the body-wall. The latter consists almost exclusively 

 of a thick layer of soft gelatinous connective-tissue covered externally 

 by the epidermis, internally by the peritoneal endothelium. The con- 

 nective-tissue shows radiating lamellae, comparable to those which lie 

 parallel to the surface in the ordinary subcutaneous tissue. They retain 

 their primitive character as a cellular network in process of exoplasmic 

 transformation. The interlamellar spaces, which are much reduced in 

 the subcutaneous tissue, are much enlarged in the umbilical cord, and 

 contain an abundant amorphous coagulation of lymph and albuminoids. 

 This is probably a secreted product, and it is quite distinct from the 

 hyaline substance of the lamellae. 



Primary Marrow-cell. f — Stanislaus Klein describes from the 

 normal bony marrow of man a distinctive element which he calls the 

 " Myelogonie " or primary marrow cell. It is distinct from myeloblasts 

 and erythroblasts. It is a new kind of leucocyte. It is the mother-cell 

 of all the myeloblasts, megaloblasts, magakaryocytes, and polykaryocytes 

 — perhaps also of the lymphocytes. It may be identical with the " large 

 embryonic lymphocyte " of Maximow and with the " H&miogonie " of 

 Molliers. 



Plastosomes in Epithelial Cells of Trachea and Lungs. J— Fr. 

 Meves and R. Tsukaguchi have studied the epithelium lining the trachea 

 and lungs (in the rat and cat), and find that there are plastosomes in the 

 form of threads. In the ciliated cells there is a coil-like aggregation of 

 wavy or sharply-bent plastokonts below the fringe of cilia, and from 

 this coil a few straighter threads run past the nucleus to the base of the 

 cell. In some other cases, e.g. the nucleated epithelium of the alveoli, 

 the plastosomes are abundant, sometimes as granules, sometimes as rods, 

 sometimes as threads, and usually diffused through the whole cell. 



* C.R. Soc. Biol. Paris, lxxvi. (1914) pp. 800-1. 



t Die Myelogonie als Starurnzelle der Knochenmarkszellen. Berlin: 1914, 

 140 pp. (10 pis.). 



X Anat. Anzeig.. xlvi. (1914) pp. 289-92 (6 figs.). 



