14 
and their relationship insisted upon. Lastly the history of the 
wing was dealt with ina similar fashion, the clawed thumbs of 
the adult ostrich andembryo duck, the clawed digits of the nestling 
Hoatzin, &c., were shewn in diagram, and their importance as 
evidence of reptilian ancestry suggested. The anchylosed finger- 
bones were taken as evidential of flight and that even the ostrich 
is descended from forms which enjoyed aerial, or at least an 
aquatic form of flight for a longer or shorter period, as is shewn 
by the persistence beneath his plumes not of any form of de- 
graded foot or paw, but of a true wing, albeit its lizard ancestry 
is denoted by a claw. 
WEDNESDAY, JANUARY 11th, 1893. 
AN EVENING FOR SPECIMENS, &c. 
Amongst the objects exhibited the most interesting was “ A 
tooth impregnated with Phosphate of Iron,” by Mr. Charles 
Dawson, F.G.S., who has kindly contributed the following Notes 
on it. 
The tooth is apparently one of the lower incisors of a calf 
(deciduous) (Bos).—As the incisors of Bos vary only slightly, it 
would be difficult to determine if the tooth may belong to one of 
an extinct species. The specimen was obtained by me from a 
Brighton jeweller, who could not discover its history, as it had 
been bought promiscuously in a lot of precious stones from a 
dealer, and was thought to be turquoise. 
It was examined by the Keeper of the Mineralological Depart- 
ment at the British Museum, who on superficial examination 
thought it was artificially coloured by a copper salt. Upon 
analysis, however, no traces of copper were discovered, and there 
were zron reactions. 
The front surface of the tooth has been artificially polished, 
ready for cutting by the trade as a turquoise. The colour is said 
to be that of a fine Persian turquoise, and is probably more per- 
manent, the colour of the turquoise proper being notoriously 
