450 



NA TURE 



[March 9, 1905 



the Dip, and thirty-two of the Intensity, with fifty-two of 

 the Declination. 



The observations of the Declination were made with 

 the ship's standard compass in the process of " swinging." 

 Those for Dip and Intensity at the same time with the 

 Lloyd-Ci-eak (shortly L.-C.) dip circle, an instrument origin- 

 allv designed for sea observations of those elements, but 

 which in field work on land has also been found to give 

 results hardly inferior to those of the specially designed 

 land instruments. The degree of accuracy hitherto obtained 

 at sea as compared with land observations with the same 

 instrument is also given. 



The accompanying illustration shows the L.-C. circle 

 mounted for observations on land and fitted on top with an 

 arrangement proposed by the L".S. C. Survey for observing 

 the Declination, but which also serves the purpose of 

 placing the circle in the magnetic meridian. \\ sea the 

 circle is mounted on a gimbal stand with the declination 

 fitting removed, as the angle between the direction of the 

 ship's head and the magnetic meridian is then obtained 

 from the ship's standard compass. 



.\ detailed description of the L.-C. circle is given in the 



report w'ith the methods adopted for observing therewith at 

 sea in the U.S. surveying vessels, which are, however, 

 not specially adapted to the work. A wood-built vessel, 

 specially designed and devoted to magnetic work as a 

 primary object, is required to obtain the full value from 

 this instrument, and it is therefore pleasant to record that 

 the magnetic survey of the Xorth Pacific Ocean in such a 

 vessel will be commenced this vear bv the United States. 



THE NEST OF THE FIGHTING FISH. 

 T N most, if not in all, the members of the group of Oriental 

 ■*■ fishes typified by the so-called climbing perch (Anabas 

 scaiidens), the males take charge of the eggs as they are ex- 

 tracted from the females and place them in a " nest " (if 

 mucus-covered bubbles, w-hich they have previously pre- 

 pared. A well-known representative of the family is the 

 ■■ fighting fish " {Belta piignnx), which takes its name from 

 the circumstance that a semi-domesticated breed is kept by 

 the Siamese for the sake of the sport offered by the combats 

 of the males. Of this fish living specimens from Pinang 

 have recer.tly been in the possession of -Mr. IC. H. Waite, 



of the Sydney Museuin, who has published an illustrated 

 account of their nesting habits in the Records of the Aus- 

 tralian Museum for December last (vol. v. No. 5). Mr. 

 Waite has obligingly sent us a copy of his original photo- 

 graph of the nest, which is herewith reproduced. 



Mr. Waite states that he received these fish early in April 

 last year, and that the male almost immediately proceeded 

 to blow bubbles, which it produced by rising periodically to 

 the surface and taking in gulps of air. A circular mass 

 of mucus-clad bubbles, about 3 inches in diameter, wiis soon 

 produced ; and in course of time several other layers were 

 formed, which resulted in the final production of a large 

 dome-shaped structure, as shown in the photograph. The 

 structure w'as completed on the third day, when the female 

 commenced to lay her eggs, which were received between the 

 pectoral and ventral fins as they were extruded, and were ther« 

 suffered to sink slowly in the water. Here they were col- 

 lected by the expectant male, decked in his resplendent breed- 

 ing colours, and placed, after being coated with mucus, 

 below the mass of bubbles, to which they adhered. From 

 three to seven eggs are extracted at a time, and the process 

 is continued until there are from one hundred and fifty to 

 two hundred. When the laying is over, the female is 

 kept away from the nest to prevent her devouring the eggs, 

 which are carefully tended by the male, being constantly 

 moved and from time to time re-coated with slime. 



On the third day the eggs hatched, the larvje remaining 

 beneath the shelter of the bubbles. From time to time some 

 fell off, when they were immediately replaced by the watch- 

 ful niali', but in a da\' or two the numbers which became de- 



Fn;. I.— Nest of the Fighting Fish. ,\bout two-thirds natural size. 

 From a photograph by Mr. Waite. 



tached were too many for him tu secure, although he fre- 

 quently had seven or eight in his mouth at once. Some were, 

 however, recovered from the bottom of the tank and returned 

 to the shelter of the nest, but many w'ere devoured by the 

 female. Eventually all the laria: died, and, although the 

 fishes bred on two other occasions, none of the offspring were- 

 reared. 



SOME RECENT WORK OF THE U.S. GEO- 

 LOGICAL SURVEY IX THE WE.'^TERN 

 STATES.' 

 TF it be possible for envy tu lurk in the breast of the 

 scientific W'orker, then surely might we look for it 

 in the geologist of the.se islands when he regards the 

 lot of his fellow-worker across the Atlantic- In the breadth 

 of field open to research, in the freshness of the land, and 

 in the public support accorded to his labours, the geologist 

 of the present day in the United States may justly claim 

 preeminence. In the four memoirs before us, a mere 

 random selection from the recent publications of the U.S. 



' " Zinc and Le.id Deposits of Northern Arkansas." By G. I. -Adams 

 and others. Pp. t ti ; with 17 plates and 6 figures. 



"The Copper Depjsils of the Encampment District, Wyoming." By 

 A. C. bpencer. Pp. 107 ; with 2 plates (maps) and 49 figures 



■■Economic Resources of the Northern Black Hills." By J. D. Irving 

 and others. Pp. 222 ; with ao plates and 16 figures. 



■'A Geological Reconnaissance across the Bitlerroot Range and Clear- 

 water Mountains in Montana and Idaho." By W. l-indgren. Pp. 1^3 :, 

 with 15 plates and 8 figures. 



Being '■Professional Papers" Nos. 24, 25, 26 and 27 of the U.S. Geo- 

 logical Survey. (Washington, 1904.) 



NO. 1845, VOL. 71] 



