508 



On Gigantic Land-Tortoises. 



[Jan. 25, 



sufficient to secure perfect immunity from external contamination, were 

 found utterly ineffectual. 



Thanks to the friendly action of the President of the Eoyal Society, I 

 was enabled to escape from this atmosphere to a purer air. I had a 

 series of tin chambers constructed, which were not permitted to enter 

 the Eoyal Institution at all, but were taken straight from the tinman to 

 Kew Gardens. They were mounted in the excellent laboratory recently 

 erected there by the munificence of Mr. Jodrell. In this new position 

 the insuperable difficulties encountered in London disappeared, and the 

 experiments followed the course of those described in my last investiga- 

 tion. Two of the chambers gave way; but on being scrutinized they 

 were found leaky. Five sound chambers, on the contrary, remained 

 perfectly intact, and they embraced the particular substances which had 

 given me so much trouble in London. Infusions exposed to the common 

 air at Kew became rapidly rotten. 



A fuller account of these researches shall soon be submitted to the 

 Royal Society. In prosecuting them thus far I have been very ably 

 assisted by Mr. Cottrell and his junior colleague ]Mr. Frank Valter. 



January 2d, 1877. 

 Dr. J. DALTON HOOKEE, C.B., President, in the Chair. 



The Presents received were laid on the table, and thanks ordered for 

 ihem. 



The following Papers were read : — 



I. Description of the Living and Extinct Eaces of Gigantic Land- 

 Tortoises. — Parts III. and IV. The Eaces of the Aldabra 

 Group and Mascarene Islands.'-* (Conclusion.) By Dr. Albert 

 GuNTHER, F.E.S. Eeceived November 30, 1876. 

 (Abstract.) 



In continuation of, and concluding, the researches into the history of 

 the Gigantic Land-Tortoises, read before the Eoyal Society on June 20, 

 1874, and published in the 165th volume of the Philosophical Transac- 

 tions, the author treats in Parts III. and lY. of the Tortoises of the 

 Aldabra Group and Mascarenes. 



By the addition of the valuable materials obtained by one of the 

 naturalists of the " Transit-of-Yenus" Expedition to Eodriguez, and by 

 the Hon. Edward ]N'e^i:on in Mauritius, as well as by the aid of sup- 

 plementary information received from other sources, the author has been 

 enabled to show in the present parts of his paper that the round-headed 



