12 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Neumann's sheaths and odontoblast continuations (dental fibres) are 

 two different well characterised formations. Neumann's sheaths line 

 the dentine canaliculi in the uncalcified and calcified zone, and pass over 

 at their central ends into a lamella, discovered by Kolliker, which resists 

 acids and alkalis like the sheaths themselves. The sheaths possess a 

 considerable power of resisting acids and alkalis, yet they are able to 

 resist decaying maceration only in the region of the calcified zone. 

 Dental fibres arise directly from the odontoblasts, and run within 

 Neumann's sheaths. 



Lymphoid Tissue in Ichthyopsida.* — A. Drzewina concludes her 

 observations on this subject. Adenoid tissue in the Ichthyopsida forms 

 a reticular framework with leucocytes in the meshes. The reticulum is 

 often clearly of a cellular character, and all kinds of white corpuscles 

 known in higher Vertebrates occur, though some possess features not 

 usual in leucocytes. There occur series of transition forms between 

 lymphocytes and mononuclears. In those Ichthyopsida without bone 

 marrow, the same organs generate, indifferently and simultaneously, 

 elements of the lymphogenic and myelogenic series. The adenoid tissue 

 is scattered through a series of organs — kidneys, wall of digestive tube, 

 liver, pancreas, heart, genital glands, etc. It occurs either in scattered 

 masses or as differentiated organs, comparable in a degree to the follicles 

 or the lymphatic ganglia of the higher Vertebrates. 



Nerve Elements in Amnion of Cat.f — M. Wolff describes in the 

 amnion of cat, sensory bodies which He a few millimetres apart. These 

 bodies are ovoid, tapering at the ends ; they are enclosed within a 

 sheath in which nuclei may be seen. The nerve entering has no sheath ; 

 it winds spirally in the bulb-shaped end organ. The coils show 

 numerous swellings, band-like flattenings, and anastomose with each 

 other. 



c General. 



Plimmer's Bodies and Reproductive Cells.! — J. Bretland Farmer, 

 J. E. S. Moore, and C. E. Walker compare these remarkable structures 

 in many cancerous growths with certain vesicular structures occurring 

 regularly in the gametogenic, but not in the ordinary somatic cells. As 

 in the case of nuclear division, so also as regards cellular inclusions, 

 there is a striking parallelism between reproductive cells and cancer-cells. 

 Both classes of cells are autonomous to a very high degree ; both possess 

 the faculty of continuous or intermittent multiplication, independently 

 of the tissue requirements of the organism ; both exhibit cellular and 

 nuclear metamorphoses whicli not only, mutatis mutandis, resemble one 

 another, but differ materially from those pertaining to the normal 

 somatic cells. 



Adipogenic Function of the Liver.§ — C. Deflandre discusses the 

 relation of this function to sexual life and its mechanism. It appears to 



* Arch. Zool. Exper., 4 ser., iii. (1905) pp. 145-76, 187-303, 309-38 (1 pi.). 



t Anat. Anzeig., xxvi. (1905) pp. 658-63. 



X Proc. Roy. Soc, ser. B, lxxvi. (1905) pp. 230-4 (9 figs.). 



§ Journ. de l'Anat. et Phys., xli. (1905) pp. 319-52. 



