ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 423 



Accessory Nuclear Structures in Spermatozoa.* — G. Retzius finds 

 in the spermatozoa of Polychasts and Molluscs peculiar spherules which 

 lie at the posterior end of the head. They are definite in number, and 

 regular in arrangement. He calls them accessory nuclear organs, and 

 compares them to the mitochondrial body. 



Influence of Ovariotomy in Goat.| — P. Oceanu and A. Babes find 

 that the removal of the ovaries has the following advantages :— (1) the 

 hircine odour of the milk disappears, (2) the duration of lacteal secretion 

 is increased, (3) there is fattening and an improvement in the quality 

 of the flesh, (4) the quantity of milk is increased, and (5) the quantity 

 of butter, casein and phosphoric acid is increased, while that of lactose 

 is decreased. 



Influence of Nervous System in Regeneration.^ — E. Godlewski 

 has made many experiments on newts which lead him to conclude, like 

 Rubin and G. Wolff, that the presence of the central nervous system is 

 absolutely essential to the normal course of regeneration. The spinal 

 ganglia cannot replace the formative influence of the spinal cord centres 

 in instituting the regenerative process. A breach of continuity in the 

 central nervous system has no influence on the normal course of re- 

 generation. The presence of the central nervous system conditions the 

 activity of the prospective potencies of those elements which are stimulated 

 by an operative effect to the realisation of their regenerative capacity. 



Regeneration of Limbs in Tadpoles of Frog.S— A. Bauer finds 

 that the regenerative power decreases with age ; that it is more effective 

 when the amputation is near the distal end ; and that it may be exhibited 

 twice or three times in regard to the same limb. There seems to be a 

 considerable difference in the regenerative power according to the time 

 of birth, for it is much more intense in young tadpoles hatched in April 

 than it is in those of July. In the latter there is a marked enfeebling 

 of the " biogenetic activity " throughout the tissues, as shown in the 

 retardation or the arrest of development. Thus the regenerative power 

 may be a function of the power to accomplish metamorphosis. 



Origin of Subclavian Artery in Chick.|| — C. G. Sabin finds that 

 in the chick the earliest circulation to the wing region (from the third 

 to the sixth day) is derived from the dorsal aorta, and that the main 

 vessel of this circulation corresponds to the sub-clavian in mammals. 

 A secondary wing circulation derived from the ventral end of the third 

 arch, not existing previous to the sixth day, is at that time established, 

 and both vessels carry blood to the wing for a time. Further, at some 

 time in the latter part of the seventh day, or the first part of the eighth, 

 the primary vessel atrophies and disappears, while the ventral artery 

 increases in size and develops into the adult condition of the subclavian. 



Origin of Lungs.f— Alfred Greil objects to the view of Goette, 

 Spengel, and others, that the lungs may be traced to posterior (sixth) 



* Anat. Anzeig., xxv. (1904) Erganzungsheft, pp. 154-6. 

 t Comptes Rendus, cxl. (1905) pp. 172-4. 



j Bull. Internat. Acad. Sci. Cracoyie, 1904, pp. 492-505 (1 pi.). 

 § Journ. de l'Anat. Phyaiol., xli. (1905) pp. 288-99 (22 figs.). 

 || Anat. Anzeig., xxvi. (1905) pp. 817-32. 

 K Tom. cit, pp. 625-32 (5 figa.). 



