488 THE CUCKOO 



noted, but no information as to the source from which the records 

 were derived. In the same year Mr. W. Wells Bladen published, in 

 the Annual Report and Transactions of the N. Staffordshire Field Club, 

 vol. xxx. pp. 30-39, a list of 145 species, of which 122 were European. 

 By means of initials in parallel columns Mr. Bladen shows which 

 species have been included in the more important published lists, and 

 also notes which species are represented in his own collection, with 

 localities. In Naumann's Naturgeschichte der Vogel Mitteleuropas, iv. 

 p. 403, Dr. Rey gives an amended list of 145 species, which is practically 

 identical with Mr. W. Wells Bladen's, and a few years later, in his Eier 

 der Vogel Mitteleuropas, pp. 94-96, he published a catalogue of 146 foster- 

 parents, of which 119 were classed as European and 27 as Asiatic. At 

 the present time it is probable that the list of Asiatic foster-parents 

 might be largely increased, but the question arises whether these long 

 lists of names, in many cases based only upon clutches bought from 

 dealers, without even the original collectors' names, have any real 

 scientific value. The fictitious value attached to a cuckoo's egg with 

 a clutch of some rare foster-parent makes deception so easy and pro- 

 fitable, that a thorough investigation of records is desirable, and it 

 would be better if only those authenticated by the testimony of the 

 finder were admitted. 



In Key's list of 1 17 species, an analysis of the records shows that 

 no fewer than 94 are recorded fewer than ten times, leaving only some 

 23 regular foster-parents. Of course this list is very imperfect, 

 especially with regard to English records, but it probably represents 

 with some accuracy the proportion of rare or accidental foster-parents 

 as opposed to regular ones in Germany. The highest number of 

 records (199 instances) is associated with the redbacked-shrike, 

 Lanius collurio L., but its position at the head of the list is due to 

 exceptional circumstances. The majority of Key's records were 

 naturally derived from his own collection, and in the Leipzig district 

 the redbacked-shrike was an exceptionally favoured foster-parent. 

 Thus out of 147 cuckoos' eggs from this neighbourhood, no fewer than 



