ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 709 



The second occurs within the chambers, and is traversed by only a few 

 of these fibres. In both kinds the Sharpey's fibres extend from the 

 proper bone-mass produced by the activity of the osteoblasts. The 

 study of the sunfish confirms the view that the chief mass of the bone 

 ground-substance is a product of osteoblast activity. 



Function of Neurofibrils.* — Albrecht Bethe discusses this much- 

 debated question, and comes to the conclusion that in spite of all criti- 

 cism the interpretation of the neurofibrils as conducting elements rests 

 on a sound foundation. There may be greater physiological certainties, 

 but the author puts this interpretation on the same level as that of the 

 contractility of myofibrils, or of the sensitiveness of the rods and cones 

 to light. 



Affinities of Mammary G-lands.t — L. Hoche brings forward a 

 number of histological facts in regard to the structure of the mammary 

 glands in health and disease, which lead him to think that their relation- 

 ships are with sudorific, salivary, and lachrymal glands, rather than with 

 sebaceous glands as is usually believed. 



Role of Chondriome in Secretion. :{: — H. Hoven has studied the 

 details of the process of secretion in pancreatic cells, and his general 

 conclusion is that the internal portion of the mitochondrial filaments 

 gives rise to secretion-granules by a process of disintegration, while the 

 basal peripheral portion persists as an active uniform filament which 

 grows rapidly, and gives rise to new chondrioconts capable of elaborating 

 more secretion-granules. 



Process of Secretion in Human Hypophysis. § — Alezais and Peyron 

 describe the behaviour of the nucleus during secretion in the glandular 

 lobe of the human hypophysis. The most interesting phenomenon is 

 the migration of the nucleolus and its dissolution in the cytoplasm. 

 There is often a clear halo-like zone around the nucleus which may be 

 replaced by hernia-like prolongations of the nucleus. The nucleus, 

 which evidently plays an active part in the secretion process, may retain 

 its integrity, but it may also undergo karyolysis and disappear. 



Peyer's Patches in Birds.|| — Ed. Batterer and Aug. Lelievre dis- 

 cuss the resemblance between these structures and the bursa Fabricii. 

 In both the closed follicles are due to epithelial cells. These proliferate 

 and are transformed into the reticular framework of the follicle and the 

 lymphocytes in the meshes. Peyer's patches and bursa Fabricii have 

 to begin with an essentially similar development, though the later 

 history of the two structures is very different. 



Nature of the Bursa Fabricii.lF — Aug. Lelievre and Ed. Retterer 

 have studied the development and retrogression of this enigmatical 



* Anat. Anzeig., xxxvii. (1910) pp. 129-38. 



t C.R. Soc. Biol. Paris, lxviii. (1910) pp. 1028-9. 



t Anat. Anzeig., xxxvii. (1910) pp. 343-51 (7 figs.). 



§ Comptes Rendus, cli. (1910) pp. 94-6. 



|| C.R. Soc. Biol. Paris, lxix. (1910) pp. 114-17. 



f Ton. cit., pp. 169-72. 



