April 30, 1886.] 



SCIEJSTCE. 



395 



oxygen, while but a trace of carbon dioxide had 

 been added to it. The water in which it had been 

 immersed had received, however, a much greater 

 amount of carbon dioxide than could have been 

 formed from the free oxygen taken from the water. 



2. Tadpoles were placed in a jar partly filled with 

 water, and the jar hermetically closed. After several 

 hours, the air was analyzed, and the free gases in the 

 water determined. These determinations showed 

 that nine tenths of the oxygen consumed came from 

 the air, and one tenth from the water ; while, of 

 the carbon dioxide produced during the experiment, 

 the air contained three tenths, and the water seven 

 tenths. 



In order that the carbon dioxide given off by the 

 tadpoles to the air might not be absorbed by the 

 water during the experiment, a layer of olive- oil six 

 millimetres thick was put upon the water. 



3. It was found by careful and repeated observa- 

 tions, under perfectly natural conditions, that frogs 

 in cold weather (so-called ' winter frogs '), in water 

 at 0° to 15° C, remain with their heads above the 

 surface from one tenth to one-half the time, and 

 while above the surface carry on from eight to 

 twenty lung respirations per minute ; showing, that, 

 under natural conditions, the respiration of ' winter 

 frogs ' is not entirely or almost entirely carried on 

 aquatically by the skin, as is commonly supposed 

 (Klug and Martin). 



4. The results obtained by Moreau and others, 

 upon the respiratory function of the air-bladder of 

 ordinary fishes, and those of Wilder, on the respira- 

 tion of Amia (the mud-fish), are in general accord 

 with the facts stated for turtles and tadpoles. 



These facts seem to us to justify the conclusion 

 that the respiratory gas-interchange in combined 

 aerial and aquatic respiration does not conform to 

 the law governing either exclusively aerial or ex- 

 clusively aquatic respiration, but that, whenever 

 aerial and aquatic respirations are combined in an 

 animal, the aerial part of the respiration is principal- 

 ly to supply oxygen, and the aquatic part to get rid 

 of carbon dioxide. S. H. and S. P. Gage. 



Anat. lab., Cornell univ., 

 April 15. 



Pharyngeal respiratory movements of adult 

 amphibia under water. 



In studying adult amphibia for possible respira- 

 tory movements under water, we have found that 

 the common newt (Diemictylus viridescens) so 

 abundant in lakes and ponds, and which is known to 

 remain voluntarily a long time under water, carries 

 on, while under water, rhythmical pharyngeal move- 

 ments almost precisely like those of the soft-shelled 

 turtles ; and, as in the turtles, these movements 

 cause a flow of water into and out of the mouth and 

 pharynx. 



The Cryptobranchus (Menopoma) has also been 

 found to draw water iuto the mouth, and to expel it, 

 in part at least, through the persistent gill-fissures. 



So far as we know, these facts have not been pub- 

 lished before. We would be glad to know if these 

 observations have been previously made on Di- 

 emictylus and Cryptobrauchus, and if similar pharyn- 

 geal movements under water have been described 

 for other adult amphibia. S. H. and S. P. Gage. 



Anat. lab., Cornell univ., April 25. • 



The germination of pond-lily seeds. 



In the issue of Science, March 21, 1884, there ap- 

 peared a conditional offer of seeds of the Nymphea 

 odorata, obtained by me in the fall of 1883, the 

 growth of that year. Many of the seeds at this 

 time were germinating ; some had developed the 

 second leaf. There was a marked difference in 

 color ; the variations were, in shades of red, from 

 blood-red to light pink, from dark blue-green to light 

 yellow green, and from a dark bronze to a light 

 salmon. It seemed to me, with varying and suitable 

 culture, new varieties might be obtained, as the seeds 

 are not always to be had, and the method of ger- 

 mination is not a matter of every-day observation. 

 A number of applications were received, but I have 

 not heard from any one, of successful culture, nor 

 whether all or any of the seeds germinated. A suc- 

 cession of germinations gave me new plants to take 

 the place of those destroyed by Unios, ferments, or 

 fungi. The seed were kept under water, on sand, 

 exposed to a north light, or that reflected from the 

 brick houses on the north side of the street, fifty feet 

 distant. 



In June, 1855, I removed from the water all light 

 seed, and those that were softened, as well as all "on 

 which fungoid growths had appeared, and placed the 

 vessel in an open space where it had vertical light, 

 and from the sun, for an hour between eleven and 

 twelve in the morning- in clear weather. A half- 

 dozen new plants appeared in August, as the result 

 of the change. When the cold weather came in the 

 fall, I restored them to their old position in the north 

 light, slightly obscured by ferns, Zygodium scan- 

 dens and Pteris serrulata. About last Christ- 

 mas I observed a new plant that had germinated 

 since being brought in in the fall. This plant was 

 removed to some submerged soil in another vessel, 

 where it is now putting forth its fourth leaf. In 

 February another seed germinated ; and, since the 

 20th of March, three others have begun to grow. 

 The last one was observed on the 3d of April. There 

 are a few more very heavy seed in the water. The 

 first plants from these seed that germinated early in 

 1884 — beginning in January — were peculiar in the 

 length of the internodes, all being very long, some 

 over an inch ; and the seeds, before germination, were 

 very light, and quite variable in color, but not as 

 much so as the foliage. 



The germinations of 1885 have shorter internodes, 

 smaller leaves, of an even green color, whilst other 

 germinations of this year have the internode reduced 

 to a minimum ; the leaves seem to start from the 

 very dense and dark seed ; and the foliage is variable 

 in size and color, but mostly in light shades of bronze 

 — salmon — with shades of pink. 



The seeds varied in their development when taken 

 from the pond in which they grew. 



Some of the plants had just begun to coil the 

 flower-stem by which to draw the seed down to the 

 bottom of the pond ; one had finished coiling, and the 

 seed-vessel was in the mud ; others were midway be- 

 tween these extremes. I mention this to show that 

 there were natural and well-known causes for the 

 variance in time of germination. 



When it is known that the ripe and fully matured 

 seeds are very dense, it will not seem so strange, that, 

 considering the great number of seeds to a single 

 flower, all ponds are not overcrowded, as by their 

 density they sink into the ooze and remain dormant. 



