ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 517 



Suprarenals of Amphibians. * — O. V. Srdinko has studied the 

 structure and development of these bodies in Rana temporaria, R. escu- 

 lenfa, Sombinator igneus, Bufo vulgaris, and Hyla arborea. They seem to 

 form a blood organ, in which the blood undergoes peculiar changes. This 

 interpretation is suggested by the occurrence, singly or in groups, of 

 erythrocytes which react to potassium bichromate like the cells in the 

 medulla, and also by the proportionally large number of venous spaces 

 which are present in the interior of the suprarenals. 



Regeneration in Amphibia. | — S. Prowazek records the minute 

 cytological appearances presented during the regeneration of the tail 

 in larvte of the salamander, the axolotl, and Triton alpestris. His 

 results agree generally with those previously obtained by Barfurth and 

 Fraisse. 



Appendages of the Branchial Arches in Fishes. % — Dr. Canna 

 M. L. Popta describes these in a large number of forms, and shows — 

 (1) that in all the cases which he studied they are specifically peculiar 

 or diagnostic ; and (2) that their form and development may be inter- 

 preted in relation to the form of the mouth and the nature of the dier. 



Nervous System and Luminous Organs of Argyropelecus hemi- 

 gymnus.§ — Kurt Handrick, in the course of his study of the luminous 

 organs and their innervation in this fish, has made a detailed study of 

 the brain and nervous system generally. He finds that the great de- 

 velopment of the eyes is associated with considerable modifications of 

 the brain. Thus the optic thalamus is unusually large, and is furnished 

 with an extra lobe, while similarly the optic lobes are greatly developed. 

 The fore-brain is small, and is partially overlapped by the great optic 

 lobes. Relatively to the size of the fish, the pineal body is very large ; 

 it is furnished with a solid stalk. Beneath the pineal organ there is 

 a well-developed parapineal body, apparently homologous with the 

 structure of the same name in Cyclostomes. It consists of a stalk, 

 dilated where it leaves the brain, and expanding distally into a club- 

 shaped swelling. The luminous organs consist of a superficial reflector, 

 visible externally, and a deeper luminous body consisting of a pigment- 

 sheath and the central light-producing gland-cells. The innervation 

 of the organs is described in detail. At the sides of the body the 

 author has discovered a peculiarly modified muscle band, which begins 

 in the region of the first spinal nerve and extends backwards to the 

 tail. Its function remains obscure. 



Variations of Pelvic Plexus in Acanthias vulgaris.||— R. C. Puu- 

 nett finds considerable variation in the serial number of girdle-piercing 

 nerves, in the number of post-girdle nerves, in the number of nerves 

 forming the collector, in the number and position of the nerve-canals, 

 in the number of fin-rays, and in the number of whole vertebra. 



Asymmetry occurred in an appreciable number of cases. There 

 were differences in the two sexes, and the female is more variable. A 



* Anat. Anzeig., xviii. (1900) pp. 500-8 (8 figs.). 



t Arbeit. Zool. Inst. Wien, xiii. (1901) po. 81-124 (3 pis. and 3 figs.). 



X Ann. Sci. Nat. (Zool.), xii. (1900) pp. 139-216 (1 pi.). 



§ Bibliotheca Zoolos^ica, xiii. (1901) pp. 1-68 (6 pis.). 



|| Proc. Eoy. Soc, lxviii. (1901) pp. 140-2. 



Oct. 16th, 1001 2 N 



