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ON THE MARSH- AND WILLOW-TITS OF FRANCE. 

 By Collingwood Ingram. 



Of the many difficult and complex groups that have arisen 

 since the introduction of the trinomial system, that relating to 

 the Marsh-Tit is probably the most perplexing. Certain races 

 of this widely diffused species are admittedly distinct enough 

 and have tolerably well-defined characteristics of their own, but 

 others can only be distinguished with the greatest difficulty. 

 If we were to compare these various forms with a single type 

 only (as was formerly done), we might recognise some of these 

 subspecies with comparative ease. But lately the species has 

 been duplicated. The term " Marsh-Tit " has become less com- 

 prehensive, and is now restricted to the birds having a bluish 

 metallic sheen on the black portion of their heads (Parus 

 palustris, L.), while those with a dull, sooty-black crown are now 

 known as the Willow-Tits, having for a type Parus borealis, 

 Selys.* 



So far so good, but when we attempt to further divide these 

 two into numerous geographical forms our trouble commences, 

 and it is not lessened by the fact that the immature P. palustris 

 has more or less the same lustreless black pileum as the adult 

 P. borealis] 



Most field-naturalists maintain that the two birds differ 

 slightly (though constantly) in their mode of nidification and 

 in some of their notes. However interesting these differences 

 may be, when one recollects how notoriously versatile are 

 all the members of this family — and especially in regard to 

 their song — we cannot lay much stress on these supposed 

 peculiarities. 



Although, as I have hinted, more convincing evidence would 



* Dr. Hartert takes the American P. atricapillus for the type species 

 in his ' Vogel du palaarktischen Fauna ' (vol. i. pp. 376 et seq.). 



