27 [Vol. xxxvi. 



which was which, yet there is no connection between the 

 three genera Pro/msser, Minla, and Siva. 



The next box to which I would draw your attention is one 

 containing unicoloured eggs, and is only shown because I 

 once had ray attention drawn to the fact that so many of 

 the small Thrushes (Chats, Nightingales, etc.) laid eggs of 

 this description. The box exhibited shows that these birds 

 hold no monopoly of unicoloured eggs : the eggs in it are 

 taken from the families of Thrushes, Chats, Babblers, 

 Shortwings, Weaver-birds, Sunbirds, etc. 



Having said so much and produced so many boxes which 

 all go to show how difficult it is to prove my own opinion, 

 I will now ask you to inspect the other boxes of my exhibit, 

 each of which contains a series of different genera of 

 Thrushes, a family which I have selected as being one of 

 the most wide-spread and best known. At the same time 

 the eggs exhibited are mostly of the rarer genera, not only 

 because they may be more interesting, but because so many 

 of those present will be able to fill up the gaps from their 

 own personal knowledge of Thrushes' eggs. For instance, it 

 would be easy, I am sure, for Messrs. Jourdain, Bunyard, and 

 others to produce series of the Common Song-Thrush and 

 Common Blackbird which would completely fill the gap 

 between the genera Moniicola and Geocichla as shown here. 



The series of true Thrushes^ eggs runs from the blue eggs 

 of Monticola to the extremely erythistic eggs of Petrophila, 

 and it is remarkable that these two genera which lay eggs 

 composing the extremities of the series are, by many 

 ornithologists, combined under one and the same genus. 



The E-ev. F. C. R. Jourdain, replying, said that it was 

 erroneous to state, as Mr. Pycraft had done, that Garrod^s 

 classification was not founded upon the presence or absence 

 of the ambiens muscle, as Garrod had divided all birds into 

 two subclasses according to this character. 



The value of oological characters, as regards the larger 

 group of birds, was shown by the fact that the results achieved 

 by the labours of anatomists during the last fifty years were 



