Proceedings of Learned Societies. 237 



diticms observed, he thought that land-ice, moving from central 

 plateaux downwards and outwards, has effected the extensive 

 erosions referred to, both in Scotland and other northern regions, 

 at a time when the land was at a much higher level than at present. 

 This must have been followed by a deep submergence, to account 

 for the stratified and shell-bearing drift-beds. 



ZOOLOGICAL SOCIETY.— February 28. 



Incubation of the Python. — Mr. Bartlett exhibited a young 

 python, taken on the 15th day of incubation from an egg which had 

 been detached from the general mass ; the animal was about 6 inches 

 in length, the eyes were very distinctly visible ; estimating the deve- 

 lopment as equal to that of a chick on its seventh day, Mr. 

 Bartlett calculated the full period of incubation as being seven to 

 eight weeks. In connection with Mr. Negretti, who had constructed 

 some exceedingly delicate thermometers for the purpose, Mr. Bartlett 

 had made a number of observations on the temperature of the incu- 

 bating python. 



The temperature of the air in the room was maintained at about 

 55° Fahr., that of the water-bath heating the sand on which the 

 animals rested was 74° ; on the 12th of February the temperature 

 of the incubating female on the surface of the body was 73°, that of 

 male in same den being 70°*2, whilst between the coils the female 

 was 81°'6, the male only 74°"8. On the 23rd of February, the sur- 

 face of the body of the female was 75°'4, that of the male 71 D- 8. 

 Whilst between the coils the female was 83° "2, the male 74°. Ob- 

 servations made subsequently to this date showed a still greater 

 difference of temperature between the two sexes, amounting on 

 March 2nd to 20°, the female being 96°, the male only 76° between 

 the coils. Some days after this, the female left the eggs and bathed 

 in the tank placed in the den, changing her skin at the same time. 

 After that her temperature fell considerably, and she did not for 

 some days incubate the eggs with the same closeness as before. On 

 March 16th the temperature was again carefully tested, the at- 

 mosphere of the den was 66°. That of the male on the surface 

 of the body 72°'4, between the coils 77°'6 ; whilst the temperature 

 of the incubating female was 77°'Q on the surface, and 86 c between 

 the coils ; but as an outer coil was tested, it is probably that a 

 higher temperature may exist between the innermost coils. On the 

 25th of March, the eggs were examined as far as practicable. Many 

 of them promise to be productive ; others have collapsed. The fe- 

 male python is now only 10° hotter than the male, instead of 20°, as 

 formerly. She has now been incubating nine weeks. 



On the Red Cokptjscles op the Blood op Vertebrata, by 

 Professor Gulliver, F.R.S. — There have been two parties differing 

 essentially in their conclusions as to the structure of the corpuscles 

 of the blood, both correct as far as they went. The first party, of 

 which Hewson was the representative, insisted that the red corpuscle 



