The Zoologist— January, 1871. 2421 



of passages fmther on which I had niarlied for citation, but which 

 must be sacrificed on the altar of economy. 



" The ringed plover, or ' stonehatcb,' as it is locally termed, breeds from 

 March to Julie on Thetford "Warren. "Whether the same bird lays more 

 than once in the season I cannot positively say, but I have little doubt 

 that such is the case. It certainly is so if the first eggs are destroyed or taken 

 away. The 7th of February is the earliest date on which the species was 

 ever observed by my brother or myself in that neighbourhood, and the 1st of 

 September the latest. "We have known the first egg to be laid on the 23rd 

 of March, and have found several nests with eggs (one with a single fresh 

 egg) on the 8th of June : this was in 1851. "When the birds first arrive in 

 the district they are generally seen on the fallows, or on laud from which 

 turuips have recently been fed off. After a few days they betake themselves 

 to the warrens, and remain there for the summer, frequenting the most 

 barren spots. The uests are somewhat deep holes, apparently formed by 

 the birds themselves, and having at the bottom a considerable number of 

 small stones, almost enough to fill half the hole, and neatly arranged. On 

 this pavement, whence they derive their ordinary appellation, the four eggs 

 are laid, with their pointed ends invariably meeting in the centre of the 

 nest. The cock bird has a regular song, in which he indulges during flight 

 at this season." — P. 84. 



1 should forbear making further extracts about plovers, but Mr. 

 Stevenson has touched on a subject which is one of peculiar and 

 especial interest to myself, the possible existence of two species 

 mixed up together and having a number of characters in comraonjyet 

 perfectly and permanently distinct. 1 have wearied entomologists 

 with this subject, endeavouring to show them that two insects may 

 approach so nearly in appearance that in a mixed series even the 

 eye of a Doubleday might fail to separate them, and yet that they 

 ever maintain that distinctive difference which I have suggested is 

 the only infallible characteristic of a species, that they reproduce 

 through countless ayes perfectly euyenesic offspring : colour, size, 

 and even conformation — the very shape of the skull itself may vary 

 indefinitely ; and yet if, as with our pigeons and our dogs, there is 

 no limit to the perfect fertility of their descendants, I can entertain 

 no doubt whatever that differences, whether naturally or artificially 

 produced, are of less than specific value: some will plead that the 

 skill of man might by perseverance create a species; others that 

 geographical or ciimatal conditions might effect the same undesir- 

 able object ; others again that " natural selection," the choice of the 



SECOND SERIES — VOL. VI. C 



