154 Proceedings of Learned Societies. 



riments to the fact of the ova being placed deep in the water, as 

 they will not develope even when submerged a few inches. 



Dr. Edwards also stated that light was essential to the meta- 

 morphosis from the tadpole to the frog, stating that tadpoles deeply 

 submerged in a perforated box in the river Seine do not become 

 transformed. Mr. Higginbottom maintains that the arrest of deve- 

 lopment is to be attributed to the seclusion from the atmospheric 

 air, and not from light, as the tadpoles, both of the frog and triton, 

 obtain their perfect development in the dark rock-cellars of Not- 

 tingham, the rapidity of the change varying with the temperature. 

 He states, that " The situation in which Dr. Edwards placed the tad- 

 poles, ' some feet below the surface of the river ' in his experiment, 

 would inevitably prove unsuccessful in the full development of the 

 frog. I have always found the transformation, both of the triton 

 and of the frog, equal, in the same temperature, both in the light 

 and in the absence of light, if placed in shallow water ; but during 

 their metamorphosis they must be allowed to rise to the surface of 

 the water to obtain air, or they become asphyxiated. To prevent 

 this, I placed stones in the vessel, and allowed them to leave the 

 water for the purpose of atmospheric respiration. The metamor- 

 phosis of the tadpole, when at its full growth, requires about fourfceeu 

 days to bring it to the condition of a frog. About the termination 

 of that period, the diminution of the body is so great, and also the 

 absorption of the expanded caudal extremity is such as to diminish 

 cutaneous respiration. Respiration by the lungs becomes absolutely 

 necessary to prevent the animal from becoming asphyxiated, which 

 would be the case if it remained in the water ; requiring then not 

 an aquatic, but an atmospheric medium of respiration. It may be 

 observed that after the tail is partially absorbed, leaving only a por- 

 tion of the solid part, the asphyxiated state has commenced ; the 

 little animal, with open mouth, gasps for breath ; but if removed 

 into atmospheric air, the mouth is directly closed, and respiration is 

 effected through the nostrils with perfect freedom ; the animal is 

 restored directly, jumps about and is lively." 



EOYAL GEOGRAPHICAL SOCIETY.— Jwmwry 27. 



Ascent of Kilimandjaro. — Mr. Thornton's paper on the Ascent 

 of Kilimandjaro was read. The journey of the Baron von Decken 

 and Mr. Thornton, from the coast to Kilimandjaro and back again, 

 occupied 101 clays. The mountain was ascended to the height of 

 8000 feet ; and was seen to be incontestably snow-capped. The 

 scientific confirmation of the statements of Mr. Rebmann is satis- 

 factory, in the first place as settling what has long been a doubtful 

 point, viz. the existence of snow-covered mountains in Africa at so 

 short a distance from the equator; and, in the second place, as 

 proving the truthfulness of the Missionary reports. Mr. Thornton 

 states that, considering the imperfection of the instruments for 

 making calculations which ihey possessed, the observations and 

 maps of the Missionaries are wonderfully accurate. The Kilimand- 



