JlPBIL 8, 1898. ] 



SCIENCE. 



485 



Fig. 4 is an air curve plotted from figures 

 given in Dalong and Petit's paper. It is 

 drawn to such a scale that the rate of heat 

 conduction at atmospheric pressure is the 

 same as in my own experiment with air in 

 the large bulb, and illustrated in Fig. 2. The 

 first five stations in the curve are the ones 

 from which they deduced their ' Sixth Law' 

 of cooling. The rest of the cm-ve is drawn 

 in accordance with that law, and the vac- 

 uum line represents exactly the value they 

 assigned to the cooling power of an absolute 

 vacuum. Comparison with Fig. 2 shows 

 how much they erred in their deductions. 



A study of the curve embodj'ing the re- 

 sults obtaiued with a mixture of three vol- 

 umes of hydrogen, and five volumes of 

 carbon dioxide in a small bulb, shows that 

 the carbon dioxide interfered very greatly 

 with the performance of the hydrogen. Be- 

 fore any exhaustion was made, the hy- 

 drogen alone would have done more than 

 three times the work of both gases. It was 

 not until the pressure had fallen to about 

 one hundred milliouths that both gases 

 combined, did as well as the hydrogen 

 would have done alone. Below this pres- 

 sure both gases contributed to the result. 



This interference of mixed gases is a 

 very interesting phenomenon, and seems 

 to warrant the careful investigation which 

 it is my intention to give it. 



Charles F. Brush. 

 Cleveland, O. 



THE BREEDING OF ANIMALS AT WOODS HOLL 

 DURING THE BIONTH OF MARCH, 1S9S. 



Through the courtesy of the United States 

 Commissioner of Fish and Fisheries, several 

 naturalists have been enabled to make use 

 of the equipment of the Biological Station 

 at Woods Holl during the past month, and 

 the following notes may be of interest to 

 those who contemplate pursuing lines of in- 

 vestigation at either of the marine labora- 

 tories : 



The water has swarmed with animal life, 

 and many forms rarely or never captured 

 during the warmer months have been found 

 in abundance. Breeding animals have 

 yielded rare embryological material, and all 

 forms of life have had great vitality, due 

 probably to the low temperature of the 

 water. The temperature of the water has 

 ranged from 38 F. at the beginning of the 

 month to 43 F. on the 30th. Its specific 

 gravity has varied from 1.0232 to 1.0236. 

 Among vertebrates the winter flatfish 

 (P. americanus) has been taken in large 

 numbers, and spawning individuals have 

 yielded an abundance of embryos and 

 young. The clustered eggs of the small 

 sculpin (Acanthocottus ceneus) have been 

 taken from nets and from sea-weed, and 

 the young have been conspicuous in the 

 Auftrieh. The surface towings have also 

 yielded young of the common cod {G. cal- 

 larias), eggs of which were hatched at the 

 Station during the earlier portions of the 

 month. Young cod, from one-half to three- 

 fourths of an inch in length, have been 

 found feeding exclusively upon Copepods, 

 and associated with them were the some- 

 what larger pollock (Pollachius virens) . The 

 G-adidte have also been represented by nu- 

 merous adult' frostfish' (Microgadits tomcod) , 

 though the breeding period of this species 

 is in December. The young of the sand- 

 launce {Ammodytes amei-icanics) , from one- 

 half to one inch in length, and of the eel 

 (^. chrysypa), from two to two and one-half 

 inches in length, have also been taken. The 

 pipe-fish (SipJiostoma fuseum) was not exam- 

 ined, though it was found in ISTarragansett 

 Bay with eggs and with young March 22, 

 1897. 



The ' alewife ' or spring herring (Pomolo- 

 bus pseudoharengus) has begun to enter the 

 fresh-water streams from the sea, though it 

 has not yet begun to deposit its eggs. 



Several Crustacea are already breeding. 

 The green crab ( Careinus granulatus) is car- 



