312 SUMMARY OF CURRENT RESEARCHES RELATING TO 



the southern coast of New England. This is important practically, since 

 the fish is valuable, and the history — which is reported in detail — is of 

 scientific interest, since it furnishes evidence that life on the sea-bottom 

 is subject to periodic modification, and that a species almost annihilated 

 (in 1S82) may become quickly re-established. 



Labyrinthine Apparatus of Labyrinthic "Fishes.* — HerrC. Grigorian 

 confirms Zogratf' s conclusion that this strange apparatus usually serves 

 for air-breathing, and that the wall of the associated pouch is auxiliary 

 to the same function. Where the labyrinthine apparatus is less de- 

 veloped, as in Macropodus, the pouch and the mouth-cavity are specially 

 adapted for respiration, their internal surface being covered with small 

 outgrowths. Where the apparatus is quite weakly developed, as in 

 Ophiocephalus, it has only a mechanical function, and the wall of the 

 pouch serves for air-breathing. 



Colouring Matter of Electric Lobes in the Torpedinidae. f — Dr. 

 Anacleto Romano points out that, while it has long been known that the 

 lobi electrici of the brain in the Torpedo are of a lemon-yellow colour, 

 the reason of the coloration has not been investigated. Somewhat 

 similar coloration is characteristic of the electric nerve-tissue of other 

 electric fish. The author finds that it is in all cases due to the presence 

 of fat, which not only impregnates the protoplasm of the cells, but 

 surrounds the cells themselves, and interpenetrates the somewhat sparse 

 neuroglia. This fat contains yellow lipochrome pigment and also 

 haematin, and owes its colour to the combination of the two pigments. 

 By experiment, the author has convinced himself that the function of the 

 fat is to protect the nerve-tissue by its high resistance against a centri- 

 petal electric current from the organ. 



Habits of Polypterus and Protopterus. $ — Mr. J. S. Budgett has 

 been enabled to make some observations on these two genera of fish in 

 the river Gambia. Of Polypterus two very distinct species occur, P. 

 lepradii Steind. and P. senegalus Steind. ; but the habits of the two are 

 similar. Both spawn during the rainy season in the flooded low-lying 

 plains, a regular migration taking place from river to swamp in June, 

 and from swamp to river in October and November. The females appear 

 to be greatly in excess of the males, and there are marked differences 

 between the sexes. There is no doubt that the air-bladder is used as an 

 accessory breathing organ, and the spiracle is used for the emission 

 of the air of respiration. The pectoral fins are used as organs of 

 propulsion. 



In Protopterus there is no marked external difference between the 

 sexes. The nests were not found, but fertilised eggs were obtained. 

 Segmentation is complete but very unequal, and results in the formation 

 of an upper hemisphere of small cells, and a lower hemisphere of larger 

 cells. The eg^s were not reared beyond the beginning of gastrulation. 



Plankton Variation^ — M. Bruyant has studied the variations in 

 tie plankton of Lake Chauvet during October and November. He finds 



* Zool. Anzeig., xxiii. (1900) pp. 161-70 (6 figs.). 

 t Anat. Anzeijr., xvii. (1900) pp. 177-83 (1 fip.). 

 X Proc. Cambridge Phil. Soc, x. (1900) pp. 236-40. 

 § Comptes Rendus, exxx. (1900) pp. 45-8 (2 figs.). 



