364 Royal Society : — Letters from the 



lively free from hairs, and the relative motion of tlie remaining 

 joints very much more limited." 



My experiments on the mosquito began late in the fall; and 

 therefore I was not able to extend them to other insects. This 

 spring I purpose to resume the research, and will experiment 

 especially on those Orthoptera and Ilemiptera which voluntarily 

 emit distinct and characteristic sounds. 



PROCEEDINGS OF LEARNED SOCIETIES. 

 ROYAL SOCIETY. 



December 17, 1674. — Joseph Dalton Hooker, C.B,, President, in 

 the Chair. 



Letters received from the Naturalists attached to the Transit-of- 

 Venus Expedition at Rodriguez. 



GoTemment House, Port Mathurin, 

 Kodriguez, Nov. 2, 1874. 



Deae Sib, — I write to give you a short account of my proceed- 

 ings and success here so far, in my explorations of the Rodriguez 

 bone-caverns. 



I must confess to a more or less degi'ee of disappointment on 

 my first inspection of the caverns ; and you \^ ill understand the 

 cause, I think, when I inform you that out of thirteen caves which 

 I found on my arrival, and which I believed till lately to be the 

 onlv ones, twelve bore evident, and some recent, signs of previous 

 digging. However, I set to work at once, and, with much diligent 

 search, had found five new caves by the time that we had finished 

 the first thirteen. Out of these I have reason to believe that, 

 in three of them, no mortal foot has ever been previous to mine ; 

 for the mouths of all were closed up by a falling-in of the rock ; 

 and it was bv this sign that 1 guessed at their existence. We 

 had to work some time at all of them with a big iron mallet before 

 entrance could be effected. In one of these caves I believe I found 

 the bones of two Solitaires, \s-ithout admixture of those of any other 

 individuals. Of the truth of this 1 am pretty certain ; for they 

 were clearly the bones of a male aud female which had fallen dowii 

 into a cleft, from which egress to so unwieldy a bird was im- 

 possible. 



Some of the bones had fallen into dust from exposure to the 

 air, being only partially covered with sand, whilst others had been 

 altogether removed : whether by water or not 1 could not say ; for 

 I found no trace of its action there. The same cause, decay, which 

 had nearly annihilated others might have entirely removed these. 

 I found amongst these about thirty rings uf the trachea or tracheae. 



