160 SUMMARY OF CURRENT RESEAKCHES RELATING TO 



Br. W. S. Bruce, in the zone between 00° S. and the Antarctic circle. 

 It was previously obtained by the 'Belgica' within the Antarctic circle. 

 He points out that the Macrurida?, like other fishes, are unfavourable to 

 the theory of Bipolarity, since there is no species or genus common to 

 the Arctic and Antarctic waters. 



Cranial Anatomy of Mail-cheeked Fishes.* — Edward Phelps Allis 

 completes his account of the structure of the head in the Loricati. He 

 discusses the bones, nerves, sensory canals, and blood-vessels in detail 

 and comparatively, and the position of particular types, such as Gottus 

 and Dactylopt&rus. He pays particular attention to the myodome, in 

 Dnctylopterus, for instance. The myodome of fishes is primarily a sub- 

 pituitary space that is connected with the orbit of either side, or with 

 the orbital region, by a canal that transmits the pituitary vein. Second- 

 arily, this subpituitary space acquires a wide communication with the 

 orbits, the primal cause of this secondarily acquired communication 

 apparently being a deepening of the hind ends of the orbits, due to a 

 marked enlargement of the eyeballs. Following this deepening of the 

 orbits, certain of the eye-muscles of either side enter the pituitary canal, 

 and, enlarging that canal, finally wholly break down the wall that 

 separates the orbits from the subpituitary space. It seems possible 

 that the subpituitary space may represent the conical depression on the 

 anterior surface of the body of a vertebra, the later acquired, posterior, 

 or basi-occipital extension of the myodome possibly being due to the 

 assimilation of similar depressions in more posterior vertebrae. 



Supposed Evidence of Mutation in Malthopsis.f — R. E. Lloyd 

 reports on the deep-sea fishes caught by the ' Investigator ' in the Indian 

 Ocean since 1900, describing five new genera and nineteen new species. 

 The collection includes five types of the genus Malthopsis, and there is 

 some evidence that they illustrate mutation, round 31. lutea, as regards 

 their shape and their dermal ossicles. Among the offspring which the 

 members of the species are producing, are some which differ widely from 

 their parents as regards shape and ossicles, and the same kind of differ- 

 ence is occurring in widely separated localities. 



Study of Heart-action in Fish Embryos.J — A. v. Tschermak has 

 studied the action of the heart in embryos of Gobius and ScylUum, and 

 also in young lampreys. He finds that the embryonic heart has from 

 the beginning of its activity the fundamental characteristics seen in the 

 adult heart — the refractory phase, the compensatory pause after extra- 

 systole, the maximum reaction, and so forth. There are, indeed, pecu- 

 liarities in the embryonic heart, but the essential features are the same 

 as in the adult, which shows that the establishment of innervation is not 

 indispensable. The essential myogenic properties of the heart are even- 

 tually modified in a characteristic way by the neurogenic conditions. 



Olfactory Organ of Teleosteans.§— It. H. Burne has studied the 

 structure of the olfactory organ in 51 genera of Teleostei. It may be 



* Zoologica, xxii. (1909) Heft 57, pp. 145-219 (2 pis.). 



f Memoirs Indian Museum, ii. No. 3 (1909) pp. 139-80. See also Illustrations 

 of the Zoology of the Investigator Pishes, part x., pis. xliv-1. 



t SB. Akad. Wiss. Wien, cxviii. (1909) pp. 17-115 (2 pis. and 25 figs.). 



§ Proc. Zool. Soc., 1909, pp. 610-63 (26 figs.). » 



