ZOOLOGY AND BOTANY, MICKOSCOPY, ETC. 169 



various mainnials. He also found glycogen in the cells of the various 

 regions of the urinary duct system in the horse and ass. In other 

 animals the ureter and vesica epithelial-cells coloured brown with 

 potassium iodide ; only in a few isolated cells was this brown colour 

 localised in. granular masses. 



Action of Radium Rays on Skin.* — A. Exner has experimented 

 with these upon the tails of mice. The deflectible /?-rays and the 

 non-deflectible y-rays possess great power of penetration ; that of the 

 a-rays is only very trifling. Notwithstanding the fact that most of the 

 rays are deflected by means of the magnet, their effects upon the skin 

 are not different from those of the non-deflectible component. 



Fauna of the Gulf of Trieste.! — E. G-raeffe deals with the Cheeto- 

 gnatha, Gephyrea, Annelida, and Enteropneusta. He gives particulars 

 regarding the place of occurrence, mode of life, time of appearance and 

 of spawning, in various species. 



Tunicata. 



The Visual Organ of Salpa.J — W. Redikorzew finds that the 

 solitary and chain forms of the same species have eyes which are 

 structurally different. All solitary forms have the same type of eye ; 

 the chain forms, on the contrary, show r great diversity in this organ. 

 Besides the chief eyes, supplementary visual elements are present, which, 

 however, are unequally developed. The author describes the eyes in 

 histological detail. His observations have suggested the view that 

 primitive Tunicates possessed visual organs in a paired series extending 

 caudalwards from the head end, and that each pair probably corre- 

 sponded to a somite. 



IN VEBTEBBATA. 



Mollusca. 

 a. Cephalopoda. 



Photogenic Organs in the Eye of a Cuttlefish.§— L. Joubin 

 describes in Leachia cyclura six luminous organs, one on the dorsal 

 surface and five on the posterior margin of the eye. Each is surrounded 

 by a connective-tissue envelope, and contains large photogenic cells and 

 a lens. The lens arises from epithelial and deeper cells, and in most of 

 the organs is surrounded by a cartilaginous ring. The organs differ 

 from one another in detail, and may have different luminous effects, 

 possibly resulting in a specific " recognition-mark." 



$. Gastropoda. 



Salivary Glands of Snail. || — M. Pacaut and P. Vigier describe five 

 chief phases in the salivary cells of Helix pomatia — punctate, alveolar, 



* SB. Acad. Wiss. Wien, cxiii. (1904) pp. 185-8. 



t Arbeit. Zool. Inst. Univ. Wien, xv. (1905) pp. 317-32. 



t Morphol. Jahrb., xxxiv. (1905) pp. 204-39 (1 pi.). 



§ Bull. Mus. Oceanogr. Monaco, No. 33 (1905) p. 13. See also Zool. Zentralbl., 

 xii. (1905) pp. 478-9. 



|| Ver. Anat. Ges., xix. Vers. See also Anat. Anzeig., xxvii. (1905) Erg. beft, 

 pp. 151-3. 



