380 Scientific Intelligence. 



11. On the Egg and Tadpole of Batracian Reptiles. — At the sitting of 

 the Academy of Sciences of the 13th February 1826, M. Dutrochet read a 

 memoir on this curious subject. Spallanzani had conjectured that the egg 

 of the Batracians was nothing but the tadpole itself in a spherical form. 

 This opinion was at first doubted by M. Dutrochet ; but future examina- 

 tion discovered to him, that, among this class of reptiles, the foetus exists 

 prior to fecundation, which, as is well known, does not occur till the ex- 

 trusion of the egg ; and that this foetus is a kind of polypus — a simple 

 ^lobular sac, which, containing the emulsive matter for the nutrition of 

 the tadpole, lengthens gradually into a plicated tube with numerous con- 

 volutions. M- Dutrochet had formerly remarked, in his examinations of 

 insects, that the larvae of the bee and wasp -might also be found in the 

 egg before fecundation in a similar state. — Le Globe, No. 24, Fev. 1826. 



BOTANY. 



12. M. Ramond on the Vegetation of the Summit of the Pyrenees. In a 

 memoir on this subject read at the Academy of Sciences on the 16th Janu- 

 ary 1826, M. Ramond remarks, that, from the base of a high mountain to 

 its summit, the vegetation presents a foreshortened view of the same modifi- 

 cations which are observed from the same base to the Poles. In proof of 

 this, M. llamond describes the Pic du Midi, which rises 1500 toises above 

 the level of the sea. On its summit, the barometer stands between 19 inches 

 and 20 inches 3 lines. The greatest height of the thermometer, in sum- 

 mer, does not exceed 62° or 63° of Fahrenheit, and by supposing that, at 

 that height, the variations will be proportioned to those at the level of the 

 sea, the minimum will be 35° or 36°. On the same principle it will 

 be found, that the thermometer should descend in winter, in places in- 

 accessible to man, to — 14° of Fahrenheit. Hence M. Ramond concludes, 

 that the temperature on the Pic du Midi varies between the same limits 

 as in regions situated between 65° and 70° of latitude. 



" I have ascended, says M. Ramond, 35 times into this island, lost in 

 the middle of the vast ocean of air, and I have remarked, that not a flower 

 appears till the summer solstice. The spring consequently does not begin 

 at that height till the summer has commenced at the foot of the mountain." 

 This peak is accessible only during three months of the year. The month 

 of September is the most convenient for ascending it. In July and August 

 it is not uncommon to see snow fall, which remains for a long time. 



M. Ramond, even in that climate, has collected 130 species of crypto- 

 gamic or phanerogamous plants, which preserve themselves under the 

 snow. On a small spot, accidentally laid bare, he observed 7 species of 

 plants which vegetated vigorously. 



It is a curious circumstance, that the species observed in the Pic du 

 Midi are related to the same genera as the species collected by Captain 

 Parry in Melville Island, near the Pole. This island, notwithstanding its 

 extent, presents only 113 species, which is 17 less than M. Ramond has 

 collected on the Pic In the island, as on the Pic, there is only one shrub, 

 whkih is the willow, reduced to the same dimensions- The climate, 



